Fate of remaining hostages uncertain as standoff at Kenya mall continues after attack that killed 68 people!

 Helicopters circling overhead, Kenya's military launched a major operation Sunday at an upscale Nairobi mall and said it had rescued "most" of the hostages being held captive by al-Qaida-linked militants during a two-day standoff that killed at least 68 people and injured 175.

The military assault began shortly before sundown, with one helicopter skimming very close to the roof of the shopping complex as a loud explosion rang out, far larger than any previous grenade blast or gunfire volley.

Kenyan police said on Twitter that security forces had launched a "MAJOR" assault to end the bloody siege.

"This will end tonight. Our forces will prevail. Kenyans are standing firm against aggression, and we will win," Kenya's National Disaster Operation Centre said on Twitter.

The Kenya Defense Forces later said it had rescued "most" hostages and had taken control of most of the mall, though it did not provide details.

Many of the rescued hostages – mostly adults – were suffering from dehydration, Col. Cyrus Oguna, a military spokesman, told The Associated Press. He refused to say how many hostages were rescued or how many were still being held. He said some of the attackers had "most probably" been killed in the operation.

The assault came about 30 hours after 10 to 15 al-Shabab extremists stormed the mall Saturday from two sides, throwing grenades and firing on civilians.

Loud exchanges of gunfire rang out from inside the four-story mall throughout Sunday. 

Kenyan troops were seen carrying in at least two rocket-propelled grenades. Al-Shabab militants reacted angrily to the helicopters on Twitter and warned that the Kenyan military action was endangering hostages.

Kenyan authorities said they would do their utmost to save hostages' lives, but no officials could say precisely how many people were being held captive. Kenya's Red Cross said in a statement, citing police, that 49 people had been reported missing. Officials did not make an explicit link but that number could give an indication of the number of people held captive.