KOLKATA, Jan 23: The Indian police were working with the US Federal Bureau of Investigation in the probe of Tuesday’s attack on a US cultural centre in Kolkata that killed four security guards, a police official said on Wednesday.

Soumen Mitra, deputy commissioner of the detective department in the Kolkata police force, told a news conference he met an official from the Federal Bureau of Investigation on Wednesday.

“We are taking help from the FBI,” he said, without giving further details.

The police official said they had questioned 55 people in connection with the Tuesday’s attack.

“We have narrowed down our options and I am confident of a breakthrough shortly,” Mitra, who is heading the investigation, said.

“We have examined about 55 people and all of them are Indians,” he added. —Reuters