What we know about Dhaka cafe siege

A group of gunmen stormed a cafe in an upscale district of the Bangladesh capital and held dozens hostage of hours, ending in the death of 20 people.

WHAT HAPPENED IN THE DHAKA CAFE SIEGE:

* About 9pm local time on Friday security guards in Gulshan district of Dhaka, popular with expatriates, notice several gunmen outside a medical centre

* When they move to confront them, between six and 10 gunmen storm Holey Artisan Bakery; upstairs is the O'Kitchen Restaurant

* The gunmen chant "Allahu Akbar" (God is Great) as they fire their guns in the cafe

* Two police officers killed in initial exchange of gunfire

* Authorities say another 25 officers and one civilian wounded

* 12-hour stand-off begins

* Attempt at negotiation fails

* 7.45am local time, Saturday, about 100 commandos launch rescue operation

* Six attackers shot dead, one captured

* 13 hostages rescued, including one Japanese, two Sri Lankans; reports say also an Argentine and two Bangladeshis

* 20 hostages dead, thought to be all foreigners, killed by "sharp weapons"

* A number of Italians dead, reports say 10 of them

* Seven Japanese working for aid organisation unaccounted for

* Islamic State group claims responsibility, according to SITE Intelligence Group, posts video.