Kenyan security forces said Sunday night that most of the hostages being held by Al-Shabaab terrorists in a shopping mall in the capital Nairobi have been rescued, Al Jazeera reports.

The terrorists belonging to the Somali group stormed the Westgate shopping center on Saturday using grenades and assault rifles. The attack has left at least 68 people dead and more than 150 wounded, according to the Red Cross.

Gunfire and an explosion were heard from the shopping center after dark on Sunday, as security forces intensified efforts to end the standoff amid fears that the death toll could rise sharply following the discovery of more corpses by security men inside the building.

Col. 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.

Kenya’s Disaster Operation Center said “this will end tonight. Our forces will prevail.” Security forces also said that most parts of the mall had also been secured, according to Al Jazeera.

Meanwhile, Al-Shabaab, which has claimed responsibility for the siege, 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 added, “Kenyan forces who’ve just attempted a roof landing must know that they are jeopardizing the lives of hostages.”

Speaking to Al Jazeera later, Abu Omar, a spokesman, for the group, ruled out any negotiations over the hostages being held and said they would meet their fate.

Al-Shabaab confirmed to Al Jazeera that it carried out the attack in which its terrorists specifically targeted non-Muslims. Kenyans and foreigners were among those confirmed dead, including French, Britons, Indians, Canadians, Chinese and a renowned Ghanaian poet.

One Israeli, who operates a stand selling Dead Sea products in the Westgate mall where the attack took place, was reportedly slightly wounded. Three other Israelis reportedly escaped the mall unharmed.

One of the Israelis who got caught up in the attack, Yariv Keidar, described on Sunday his experience during the attack, and explained how he survived as others around him were gunned down.

One report on Sunday said that Israeli security forces have joined their Kenyan counterparts in the fight to rescue the hostages in the mall.

An Israeli foreign ministry spokesperson would neither confirm nor deny the reports.