Heavy and sustained gunfire has been heard from the Nairobi mall where Somali group al-Shabab are holed up, holding an unknown number of civilians hostage.

Three al-Shabab fighters have been killed and ten soldiers wounded in the military operation to end the standoff and nearly all hostages have been freed, Kenya's Cabinet Secretary for the Interior Ole Lenku said on Monday.

"We don't want to give you a definitive position on when we think the process will come to an end, but we are doing anything reasonably possible, cautiously though, to bring this process to an end," Lenku told a news conference.

Black smoke was seen rising over the mall complex, two days after it was stormed by al-Shabab fighters.

Lenku said a fire inside the mall was the work of the fighters, but that it would soon be extinguished.

He said that Kenyan forces were in control of all floors of the mall, and that "the terrorists are running and hiding in some stores [...] there is no room for escape".

Red Cross officials said the number of people killed so far in the siege was 62, seven lower than previously reported, due to "double counted bodies".

Kenyan forces who’ve just attempted a roof landing must know that they are jeopardising the lives of hostages Al-Shabab

Television images on Monday showed troops in camouflage running to new positions, while an armoured personal carrier was also seen shifting position

"They've got a huge job to secure the premises," Robert Hotsfall, a former officer in the British special forces regiment, the SAS, told Al Jazeera, adding that the operation would likely take another 24 hours.

Al Jazeera's Peter Greste reported from the vicinity of the mall that there was renewed shooting on Monday evening, after a brief period of calm.



Journalists and their cameras have been moved and no longer have a clear sight of the mall, but can see its perimeter.



A security official told Reuters news agency that Kenyan forces had set off an explosion, trying to get in through the roof.

Al-Shabab has said its fighters attackled the mall in relaliation for Kenya's deployment of troops to neighbouring Somalia, where al-Shabab are fighting the government.

"We do not want any negotiations with the Kenyan government," Abu Omar, al-Shabab commander, told Al Jazeera in an interview on Monday evening.

Al Jazeera's Catherine Soi, reporting from Nairobi, said that the biggest concern was that the fighters would not allow themselves to be apprehended, and that they might harm any remaining hostages.

"They went in there with a suicide mission, they knew that it was very difficult for them to get out alive. [...] The concern really is the hostages. The ministry says that they have been able to evacuate most of the people in that mall ... more than 1,000 people have been evacuated [since the siege began], but the concern is with the hostages [still in the building]," she reported.



'Suffering from shock'

Armed men belonging to the Somali group al-Shabab stormed the upscale Westgate shopping centre on Saturday using grenades and assault rifles.

Colonel Cyrus Oguna, a military spokesman, told Al Jazeera that most of the hostages had been released, though he did not provide an exact number. "Most of them were dehydrated and suffering from shock," Oguna said, adding that four Kenyan soldiers were injured in the rescue operation.

As security forces intesified efforts to end the standoff late on Sunday, al-Shabab said on its Twitter feed that the "Kenyan government shall be held responsible for any loss of life as a result of such an imprudent move. The call is yours!"

It said "Kenyan forces who’ve just attempted a roof landing must know that they are jeopardising the lives of hostages."

Al-Shabab told Al Jazeera it carried out the attack in which they specifically targeted non-Muslims. Kenyans and foreigners were among those confirmed dead, including French, Britons, Indians, Canadians, Chinese and a renowned Ghanaian poet. Speaking to Al Jazeera later, Abu Omar, a spokesman for the group, ruled out any negotiations over the hostages being held.

The group is demanding that Kenya pull troops back from neighbouring Somalia, where al-Shabab is fighting against the government.



The United Nations Security Council condemned the attack "in the strongest possible terms," and reminded Kenya that any response must comply with international human rights law.