This is a breaking story. Not all the facts are available in English yet.
In the video above, you can clearly hear: "Counter-terrorism unit" and "Islam" at around the 12-second mark.
Here is an RT article with some explanation of what is taking place.
The attack was carried out by a group of at least nine people, according to local media. They entered the restaurant at around 9:20pm local time and reportedly opened fire and set off explosions. A kitchen worker who managed to escape the building said the attackers chanted “Allahu Akbar.”
“They blasted several crude bombs, causing wide-scale panic among everyone. I managed to flee during this confusion,” he said, according to Hindustan Times.
One of the attackers was armed with a sword, the others carried guns, an employee of a nearby café told RT. He estimated the number of hostages as at least 30.
Below, US State Department presser on the situation.
Gunmen have stormed a popular cafe in the diplomatic area of the Bangladeshi capital, Dhaka, taking hostages, officials say.
Unconfirmed reports say foreigners are among those being held in the city's Gulshan district.
A gun battle between the attackers and police wounded three people, including two officers.
Police and security forces have sealed off the area and are trying to negotiate the hostages's release.
It is not clear who the attackers are, although a police officer told the BBC that Islamic militants were suspected.
Media reports quoted witnesses as saying that "Allahu Akbar", meaning "God is greatest", was heard as the attack took place.
More as it comes in.
*** UPDATE ***
BREAKING NEWS: Police locked in a shoot-out with gunmen who shout 'Allahu Akbar' as they take hostages including foreigners at restaurant in Bangladeshi capital Dhaka