Dhaka: Bangladeshi security forces on Saturday morning rescued some 13 hostages and gunned down six gunmen, ending a long drawn-out siege at a cafe in Dhaka that began Friday, officials said. The standoff between government forces and suspected Islamic State militants, which also left two policemen dead, began Friday evening after heavily armed gunmen stormed the Holey Artisan Bakery in the high-security Gulshan diplomatic zone. "The operation is over," Brigadier General Mujibur Rahman declared, nearly 12 hours after the siege began and gunmen took some 20 people hostages. Prime Minister Sheikh Hasina said that 13 hostages were rescued and condemned the Â“extremely heinous actÂ”. Â“What kind of Muslims are these people? They don`t have any religion," Hasina said in a televised address to the nation. "People must resist these terrorists. My government is determined to root out terrorism and militancy from Bangladesh." Officials said that the 13 rescued hostages included four foreigners. The identity of the rescued hostages was not immediately known. The fate of other captives was also unknown. Police declared them missing. But bdnews24.com citing an unnamed senior police officer said bodies of some foreigners have been found inside the restaurant amid fears that the gunmen may have slit their throats during the siege. However, this could not be confirmed independently. Officials said security forces were conducting mopping operation at the site and so far bodies of six gunmen have been found. Â“We have gunned down at least six terrorists and the main building is cleared but the operation is still going on," said Tuhin Mohammad Masud, a commander of the elite Rapid Action Battalion: Earlier, army men and navy commandos stormed the cafÃ© to bring an end to the deadly siege in the morning after night long intermittent exchange of fire and explosions. Armoured vehicles moved in the Gulshan neighbourhood. At least two police officers were killed in earlier exchanges of fire and 30 police officers were injured. The Bangladeshi branch of the Islamic State claimed the attack through its mouthpiece, the Amaq news agency, saying 24 people "of different nationalities" were killed and 40 others were injured. Officials citing witnesses said the gunmen shouted 'Allahu Akbar' (God is great) when they stormed into the cafÃ© and began firing blanks. This is for the first time that militants in Bangladesh have held foreigners hostage. But the deaths in the attack are the latest in a series of dozens of deadly attacks by Islamic State and Al Qaeda-linked militants targeting progressive academics, writers, activists and religious minorities in the majority Muslim country. The attack came just hours after a Hindu priest was killed in Bangladesh on Friday. The attack drew calls for Bangladesh government to act against terrorism firmly. Neighbouring India called for quick action to adopt the long-stalled Comprehensive Convention on International Terrorism (CCIT) and expressed disappointment that the UN General Assembly failed to push for its early adoption. "The perpetrators of terrorist attacks as well as the states that support and sponsor or provide safe havens to terrorists or terrorist groups must be made accountable,” India's Permanent Representative Syed Akbaruddin said, speaking at the General Assembly.