The Kenyan military first announced the news that the standoff appeared to be drawing to an end via the microblogging website Twitter late on Sunday.

"Most of the hostages have been rescued and security forces have taken control of most parts of the building," the Kenya Defence Forces said on their Twitter account.

"All efforts are underway to bring this matter to a speedy conclusion," the statement added.

Shortly afterward, the army's spokesman, Colonel Cyrus Oguna, made a similar statement in an interview with Kenyan television station KTN.

Earlier in the day, security forces had pledged to end the standoff within hours. Reporters near the upscale Westgate shopping mall had subsequently reported hearing heavy rounds of gunshots and grenade blasts coming from the complex, apparently part of a major assault by security forces.

Claim of responsibility

Between 10 and 15 al-Shabab militants were thought to be in the complex holding an unknown number of hostages prior to the final assault. The al Qaeda-linked Somali group had claimed responsibility for the attack, shortly after gunmen entered the shopping mall on Saturday morning. Before opening fire, they told shoppers that all Muslims were free to leave and that they were only seeking to kill “non-believers.” The group said the attack was in retaliation for the Kenyan military's involvement in fighting al-Shabab in Somalia.

The Westgate mall, which is located in a wealthy area of Nairobi where many United Nations workers and diplomats live, is frequented by many foreign nationals in the city.

Both Kenyans and foreigners were confirmed dead in the attack, with British, French, Indian, Canadian, Dutch, Ghanaian, and Chinese citizens reported among those who lost their lives. Over 175 people were injured in the siege, and officials said the death toll could rise after security forces have had the opportunity to conduct a complete search of the complex.

pfd/msh (Reuters, AFP, dpa)