Many unanswered questions exacerbated the void left by the death of jovial student leader Anis Khan, as his family and friends gathered to offer prayers for the youth on Tuesday, four days after his alleged murder.

The family of Anis, an Aliah University alumnus whose home is located in South Khan Para in Howrah’s Amta, has alleged that he was thrown off the top of his house by four policemen past midnight on Friday.

“This floor is under construction. Anis oversaw the work. Now that he is gone, I’m not sure if I’ll be able to take the work forward,” said Sabir, Anis’s elder brother, beside the spot from where he was allegedly thrown off past midnight on Friday.

“There wasn’t a single thing in the family that we would do without his consent. He was like a guardian, even to elders like us,” Sabir said.

“You know, my brother had enrolled himself for a postgraduate degree in journalism at Kalyani University. He appeared for online exams recently,” said the brother. “Since Saturday, so many journalists have come to our house. I wonder how it would’ve been if my brother had got the chance to become one.”

Anis, 27, used to live in a small room on the first floor of the four-storey house. It was locked since the tragedy. On Tuesday afternoon, the room was unlocked to host a prayer.

Friends and family joined hands to pray for Anis. However, even there, the demand for a CBI probe was sounded.

“May Allah bless my son’s soul…. But I want the CBI to investigate this murder and book the culprits,” said Anis’s father, Salam Khan.

In an adjacent room lives his 18-year-old niece Muskan, the daughter of Anis’s eldest sister. “Anis was her guardian. He guided her in her studies, said he had big dreams for her,” said a relative. “Muskan can’t stop crying,” said Sabir.

Munna, Anis’s friend and junior, said: “You’d give him a call and he’d come on his bike in no time. He would inspire us to do things for others. He was our leader. I don’t know who can step into his huge shoes.”

Asked if Anis talked about being close to the ruling Trinamul — something chief minister Mamata Banerjee said on Monday — Munna said: “He despised Trinamul.”

Sabir pointed at a protruded part in the exterior of the house, where he claimed Anis hit his head during the fall. Many questions remain unanswered, he said.

“Why will the police come at 1am? Why did they not have a warrant? Why was my father held at gunpoint? I still have no answers,” he said.

Anis had gone to a religious programme on Friday night. He returned late for a change of clothes. That is when the “police” had come. “Who tipped off the police about my brother’s return?”asked Sabir. Amta police had denied sending personnel over.

On Tuesday, S.Q.R. Illias, the father of jailed student activist Umar Khalid, met Anis’s family. He alleged “a political ploy” and echoed the family’s demand for a CBI probe.

People in Amta continued to demand a CBI probe, even as members of the state’s SIT visited Anis’s house.

In Calcutta, students of Aliah University took out a rally from Park Circus, vowing to reach the Writers’ Building. Students from other institutions joined in. The rally, however, didn’t follow the route permitted by the police and took a turn towards College Street from the SN Banerjee Road crossing at Moulali. There were scuffles with the police. Many agitators were arrested.

Agitation was also reported from Presidency University and Jadavpur University.