Local media in Kenya reported Monday night that there was a possibility all hostages held by terrorists in the Nairobi shopping mall have been freed, even as the police were doing a final sweep of shops early on Tuesday.

An overnight silence outside the large, upmarket Westgate mall was broken at daybreak with a loud burst of gunfire from inside, suggesting the complex had not yet been fully secured. A lone military chopper circled above.

The Kenyan government has repeatedly assured citizens that it had the situation under control.

“Our forces are combing the mall floor by floor looking for anyone left behind. We believe all hostages have been released,” the Ministry of Interior said on Twitter early on Tuesday, adding his forces were “in control” of the building.

Interior Minister Joseph Ole Lenku, told the press that three militants died and more hostages were freed in the efforts to end the ongoing siege waged since Saturday by al-Shabab, a Somali group with ties to Al Qaeda.

For more than two days, Kenyan forces have struggled to vanquish the militants, who, after killing about 68 shoppers, holed up in various corners of the mall with military-grade weaponry.

Hundreds of the best of Kenyan troops, backed by armored personnel carriers, helicopters, planes and security officials from Israel, France, Britain and the United States, were deployed to the scene, but the militants, estimated to number from 10 to 15, refused to surrender.

Lenku said evacuation of hostages has gone “very, very well” and that Kenyan officials are “very certain” that there are few if any hostages left in the building as the number of hostages trapped remains unknown.

Meanwhile, U.S. authorities are urgently looking into information from the Kenyan government that residents of Western countries, including the United States, may have been among the militants.

“We do monitor very carefully and have for some time been concerned about efforts by al-Shabab to recruit Americans or U.S. persons to come to Somalia,” White House deputy national security adviser, Ben Rhodes said.