Bangladesh police are seeking more information from friends and family of the men suspected of carrying out a deadly attack on a restaurant in the capital, with believed to have attended top schools and colleges at home and abroad.
The gunmen stormed the restaurant in Dhaka's diplomatic zone late on Friday and killed 20 people, most of them foreigners from Italy, Japan, India and the United States, in an assault claimed by Islamic State.
It was one of the deadliest militant attacks to date in Bangladesh, where Islamic State and al-Qaeda have claimed a series of killings of liberals and religious minorities in the last year while the government says they were carried out by local groups.
Whoever was responsible, Friday's attack marked a major escalation in the scale and brutality of militant violence aimed at forcing strict Islamic rule in Bangladesh, whose 160 million people are mostly Muslim.
Islamic State posted pictures of five fighters it said were involved in the atrocity to avenge attacks on Muslims across the world.
"Let the people of the crusader countries know that there is no safety for them as long as their aircraft are killing Muslims," it said in a statement.
Posts on Facebook identified the men, pictured on an Islamic State website grinning in front of a black flag, as Nibras Islam, Rohan Imtiaz, Meer Saameh Mubasheer, Andaleeb Ahmed and Raiyan Minhaj.
Most went to prestigious schools or universities in Dhaka and Malaysia, officials said. One of them was the son of a politician.
A police officer said the pictures of four of the attackers matched the bodies, although he gave a different name for the fourth.
Rohan's father, a mid-ranking leader of Prime Minister Sheikh Hasina's ruling party, had lodged a complaint in January that he had gone missing since December 30, 2015, a police officer said.
On Monday, there was nobody at the family apartment in an affluent neighbourhood of Dhaka, and a security guard said the parents had left the house on Sunday.
"A majority of the boys who attacked the restaurant came from very good educational institutions. Some went to sophisticated schools. Their families are relatively well-to-do people," Bangladeshi Information Minister Hasanul Haq Inu told India's NDTV.
Several posts on social media said the man identified by police as Nibras Islam attended Monash University in Malaysia.
A friend who knew him while he studied at Dhaka's North South University told Reuters that Islam later went to Monash.