Bangladesh police shot dead the pizza chef of a Dhaka restaurant, mistakenly thinking he was one of the militants who killed 20 people, and misread online warnings of an impending assault, police and government officials said on Tuesday. New details from interviews with the officials and the first information report registered at a Dhaka police station painted a picture of security agencies slow to deal with Friday's attack, one of the country's deadliest. "This was the first time in Bangladesh such a thing had taken place. Nobody was prepared for it. They did not realise the gravity of the situation initially," HT Imam, a political adviser to Prime Minister Sheikh Hasina, said. "Initial response was slow."

Confusion over exactly how many gunmen were involved was at least partly cleared up on Tuesday, when police named Saiful Islam Chowkidar, a pizza maker at the Holey Artisan Bakery, as among the six people security forces killed when they stormed the building to end a 12-hour stand-off.

"He may not be involved," Saiful Islam, a police official investigating the attack,said, adding Chowkidar's death was still being investigated.

An employee at the cafe, shown a photo of a man killed at the eatery and wearing a chef's outfit, identified him as Chowkidar, and said he had worked there for 18 months.

Brutal attack

In the police filing, Chowkidar's name was included among 21 hostages killed by attackers armed with knives, guns and explosives.

At least three Bangladeshis were also murdered during the assault. One was a Muslim woman, a regular at the restaurant who did not wear the Islamic veil, whose throat was slashed when she refused to recite the Koran, Imam said. Two police officers were killed outside the restaurant.

The police report showed that police made an initial attempt to enter the restaurant after the attackers stormed in, but facing gunfire and grenades they held off any action for more than eight hours. "The terrorists kept firing and throwing grenades at us every time we moved forward," the report said.

Between 30 and 35 policemen were wounded when the attackers threw grenades at a force stationed to the west of the cafe, forcing police to wait for reinforcements. Eventually, the police raid was launched after daybreak.

Imam said police repeatedly sent messages asking what the attackers wanted, initially thinking they sought a ransom. The fear was the hostages would be killed if the police forced their way in, he said.

"The way the police and the RAB acted in the early hours raises questions that need to be looked into," Imam said, referring to the Rapid Action Battalion, an elite counter-terrorism unit.

At least three of the gunmen were from wealthy, liberal families who had attended elite Dhaka schools, in contrast to the usual Bangladeshi militant's path from poverty and a madrassa education to violence.