An on-duty app-based bike taxi driver has claimed that he heard a woman screaming from an under-construction building after seeing her enter it with two men a few minutes earlier. Acting on instinct to help, he went inside, but said he was assaulted by the three.

The incident was reported at Kestopur on Saturday night.

Surya Pillai, 25, a resident of Hanapara in Kestopur, works as an app-based bike driver. As on other days, he had stepped out for work late on Saturday evening.

According to his statement to the police, he saw the three enter an under-construction building in his neighbourhood.

“He said he did not pay much heed until he heard the woman scream from inside the building. He said he immediately went to her rescue and tried to help the woman come out of the grasp of the men,” said an officer of Baguiati police station.

However, instead of coming with him, the woman started to beat Pillai and was joined by the two men with her.

“The complainant had been beaten up by all three, he told us. Maybe the trio did not want intervention, but they took the law into their hands and beat up this man who went to rescue the woman,” the officer said.

Pillai told the police that he somehow managed to escape after being attacked by the trio.

He later went to Baguiati police station to complain.

The police said they had started an investigation and were analysing CCTV footage available from the closest points to identify the alleged assailants. The sections under which the case has been drawn up based on the complaint are bailable, the police said.

This is not the first time a Calcuttan trying to save a woman being teased or molested has been assaulted. Last month, a 29-year-old man who tried to protect his woman friend from harassment by three men in a deserted neighbourhood in New Town was beaten to death.

In 2011, 16-year-old Rajeeb Das was beaten to death after he tried to resist when a group of men harassed his elder sister while she was returning from her office in Barasat.