Bangladesh commandos ended a hostage siege Saturday by storming a cafe where dozens of diners had been held captive by extremists and shot dead six of the heavily armed gunmen.

Bangladesh commandos ended a hostage siege Saturday by storming a cafe where dozens of diners had been held captive by extremists and shot dead six of the heavily armed gunmen.

Officials said 13 hostages had been rescued after members of an elite force took control of the cafe in the capital Dhaka's upmarket Gulshan quarter but there was also an unknown number of civilian casualties.

Two police officers were killed at the start of the siege, which began on Friday night as they battled the hostage-takers who were heavily armed with automatic weapons and explosives.

As the ISIL Takfiri group claimed responsibility for the attack at the start of the Eid holiday, Prime Minister Sheikh Hasina said she was determined to eradicate militancy in the mainly Muslim nation.

Hasina's government has previously blamed a string of deadly attacks on religious minorities and foreigners on her domestic opponents but the attack will heighten fears that ISIL reach is spreading.

"I thank Allah that we're able to kill the terrorists," she said in a televised address. "It was an extremely heinous act. What kind of Muslims are these people?"

Tuhin Mohammad Masud, a commander of the elite Rapid Action Battalion which led the storming operation, said that six gunmen had been killed and the situation was now under control.

There was no official word on the number of hostages who had been killed or wounded, but Masud said that "obviously there have been casualties".

Some foreigners and Bangladeshis could be seen waiting outside the cafe after the siege, still awaiting news on their loved ones inside. Commandos could also be seen roaming nearby rooftops.

Witnesses said he could hear a massive gunfight as more than 100 commandos launched the rescue operation some 10 hours after the militants seized the hostages on Friday night.

Eight hostages including a foreigner were rescued in the first few minutes of the operation. TV footage showed ambulances rushing some of those who had been freed to a military hospital.

Sri Lanka's government said two of its nationals were among the hostages rescued and were safe and unharmed.

A Japanese government official said its Prime Minister Shinzo Abe had told Hasina in a phone call that several Japanese nationals may have been inside.

ISIL claimed responsibility for the attack on the Holey Artisan Bakery cafe in Gulshan, which is home to many embassies.

Police said the gunmen burst into the restaurant as people were having dinner at around 9:20 pm and set off explosives.