Zainul Haque Sikder was a great patriot since his childhood. So he was preparing all the way to participate in the War of Liberation at any time at the call of Bangabandhu Sheikh Mujibur Rahman. This is why he could fully involve himself in the war field as a full-time fighter even at his middle age. Nothing could restrain him from doing so — not his business, riches, family, wife, offspring or the hands of his most affectionate mother. Equipped with firearms, he fought in the battle field risking his most precious possession called life. The book titled ‘Swadhinata O Muktijuddhe Faridpur (Faridpur in the War of Liberation)' authored by Mohammad Didarul Islam featured Zainul Haque Sikder’s patriotism and participation in the War of Liberation. The author is full of praise for the Zainul Haque Sikder who fought valiantly in guerilla warfare.
Another description of his active participation as a war hero is found in the book titled ‘Muktijuddhe Brihottor Faridpur (Greater Faridpur in the War of Liberation)’ by the veteran Awami League leader and active participant in the Liberation War Mr Mohammad Solaiman Ali. He quoted Zainul Haque Sikder as saying, "I came back to Jaidevpur at 7pm of March 25. At about 8 pm two young men named Siraj and Imran told me that the Pakistani Occupation forces would march on the city that night. Then and there I called and gave the news to Jessore's Haji Shaheb who used to stay at Bangabandhu's residence round the clock. Then I went to Bangabandhu's residence along with Omar and others by an EPRTC bus. We met him and urged upon him to come with us. Bangabandhu refused to come with us saying that he would do what he must do. At the same time he called upon us to do everything in order to repulse the Pakistani attack on the innocent Bengalees that night.
“We came back accordingly and created a barricade at road no 15 of Satmasjid road. At about 11 pm Pakistani army came there and started breaking the barricade. Right at that moment we started to fire by a double barrel gun from the rooftop of an adjacent building. Our fighters included Majnu, Imran, Omar, Iqbal, Siraj and others. Two Pak soldiers were shot dead. Then the Pak army started firing at us violently. We retreated from the battle on strategic ground and came back home at about 01 am. After midnight Pak army started all-out attack everywhere in Dhaka city. Sheikh Kamal's friend Firoj came to me at about 5 a.m. and informed me that the Pak army arrested Bangabandhu at about 1 am.
“On March 27, Chatra League leader Nure Alam Siddiqui was helped by me to reach the place called Ati safely. He was given a lungi and a gamcha to wear like a commoner. Then he went across the river via Rayer Bazar. The same day another veteran political leader Tajuddin Ahmed and Barrister Amirul Islam met me at Rayer Bazar brick field at about 12 am and sought my help to cross the river. I arranged their safe journey to Ati across the river.
“Previously, three young men Majnu, Emran and Siraj came to me with some rifles and Sten guns secretly in a truck. They also sought my help to keep and use the weapons. I kept one Sten gun with me. It was concealed in a bathroom of the second floor of my residence. Other weapons were sent for distribution among the students at Ati by the son of Rahim Matabbor of Rayer Bazar.”
The freedom fighters captured the Naria thana towards the beginning of September. As per earlier planning of Zainul Haque Sikder, Akkas Force Commander Jainal Abedin and FF Commander Moti Mia attacked Nariathana. On the day of attack, Zainul Haque Sikder met Subedar Zainal Abedin and Moti in a strategic meeting secretly at midnight inside a school premise four miles away from the thana headquarters to launch the assault on the enemy. Everybody advanced towards the target after the plan was finalized. A total of 80 fighters composed of liberation forces and freedom fighters took part in the skirmish. They had two LMGs, one two-inch mortar, many rifles and SLRs. Total weapons carried by the attackers were 80. Zainul Haque Sikder was the mastermind and central commander. The soldiers were divided into two groups: Akkas force under Subedar Zainal Abedin's command and FFs under the command of Nariathana commander Moti Mia. The two groups attacked the target from two sides at about five in the morning.
Nariathana police and razakars took strong shelter in their bunkers. They were about 40 in number. They had LMGs and rifles as well. As the freedom fighters opened fire on them, the enemy also fired back from their bunkers. After about one hour of exchange of bullets between the warring parties, Zainul Haque Sikder asked the freedom fighter Alamgir to advance forward in order to call upon the enemy to surrender, but he did not do so. So Zainul Haque Sikder himself advanced forward and shouted toward the enemy, 'Hands up'. The officer-in-charge of Nariathana responded to his call and surrendered raising his two hands. Nearly 30 police and razakars were killed in the battle. All the weapons of this thana were captured by the freedom fighters who won the battle convincingly. Nayek Abdur Rashid and EPR Nayek Abdur Rashid of Gosairhat also took part in this combat.
The Pak army had a strong outpost in Bhedarganj thana combining a good number of police and razakars. The freedom fighters had been planning to attack them long since. Finally October 10 was fixed as the day of attack. Zainul Haque Sikder along with Captain Babul, Zainal Abedin and Abdul Mannan Rarhi prepared the blueprint of attack in a meeting inside a school building close to Bhedarganj thana.
It was a major assault by the freedom fighters composed of 300 fighters from different sections of liberation forces. There were three strategic groups under three commanders. They were the Akkas Force led by Subedar Zainal Abedin, FFs led by Abdul Manna Rarhi and one hundred well-trained armed forces led by Captain Babul. Captain Babul's forces took position on the eastern side of the thana, and Abdul Mannan's FFs were posted on the southern street to repulse the enemy who might advance from Damudya. On the other hand, Akkas Force along with remaining fighters started the attack on the thana from the north under the command of Zainul Haque Sikder and Subedar Zainul Abedin.
At 4 am, October 10, the battle started under Zainul Haque Sikder's call. Living started from the rooftops of Dak Bungalow and both the parties got involved into a violent blood-stained confrontation. The battle continued fiercely for 22 hours. When the attack rose to its climax at midnight, the police and razakar forces inside the thana were compelled to surrender to the freedom fighters. At that very moment thousands of patriotic people chanted the slogan ' Joi Bangla' in a bid to celebrate this memorable victory. Their slogans, on the one hand, threatened the occupation forces inside the thana and, on the other, inspired the freedom fighters beyond limit. A total of 87 police and razakars were killed, whereas from the freedom fighters' side the only martyr was Havilder Mohiuddin Sardar. All the weapons were captured and the flag of the independent Bangla was hoisted there. The OC of this thana was caught red-handed while trying to escape by a way past the soldiers of Rarhi. He was killed by them brutally and his body was cut into two. Awami League leaders and workers including Abdul Hai Mia and Abul Hossain stretched their all-out help in this battle.
A few days before the assault, Palong Thana Commander Idris Master went to the camp of Akkas Force and requested Zainul Haque Sikder and Subedar Zainal Abedin to launch the attack on this police station. On the day fixed for the attack, Zainul Haque Sikder, Zainal Abedin and Idris Master again met at a house one mile away from the police station and advanced for their assault.
Their attacking forces got divided into three groups and advanced from three directions under the command of Subedar Jainal Abedin, Idris Master and FF commander Abul Quashem. The battle started at the night of September 13.
When the freedom fighters took their position for the attack, Wireless Operator Salek Khan was talking to the Officer-in-Charge of the police station. A young boy went to the thana and signaled him to come out. As soon as he did so, the attack started in full swing.
Mujib Bahini Thana Commander Fazal Master along with his forces took part in this battle. More than one hundred freedom fighters carried 4 LMGs, 2 two-inch mortars and other fire arms. Thousands of militant people led by the veteran political activists Sirajul Islam, Zafor, Jalal Master and Salek Khan raised' Joi Bangla' slogan in a tumultuous chorus that frightened the police forces and razakars loyal to Pak army. Completely demoralized, they surrendered without much resistance. Fifty five police and razakars were killed in the combat. The freedom fighters took possession of all the firearms of this police station.