Minnesota, which can clinch a wild-card playoff spot with a loss by either Carolina or St. Louis this weekend, appeared on its way to retaking the lead. But a holding penalty on Birk -- the Vikings were flagged nine times for 78 yards -- wiped out a 16-yard run by Michael Bennett that would have given them the ball at the Green Bay 40 just before the 2-minute warning.
The Vikings (8-7), though, couldn't get what they needed from a pass defense that has struggled all season.
Government spokesman Raanan Gissin said four soldiers were killed.
Six people were taken to hospital -- four badly hurt, one with moderate injuries and one lightly injured, military sources said.
The sources said another soldier remained beneath the rubble.
Gissin said rescue operations were continuing Sunday night.
The attack "indicates that unless there is decisive and sustained effort taken to dismantle the terrorist organization, it will be impossible to move towards normalizations and towards political negotiations," Gissin told a news crew. "And I think the responsibility on that lies with the Palestinian Authority."
Shortly after the first blast, a second explosion was heard in southern Gaza, but its precise location was not immediately known.
Hamas, in a phone call to CNN, said it had set off the first explosion near Rafah in cooperation with a group called the Fatah Hawks.
There was no immediate information available on that group, although it was believed to be linked to the Fatah movement formerly led by the late Palestinian leader Yasser Arafat.
Israeli military sources said it was a coordinated attack, with Palestinians firing mortar shells and guns at the post when the explosives were detonated.
It was not clear whether there were Palestinian casualties.
News video of the aftermath showed soldiers using stretchers to transport troops who appeared to be severely wounded.
In a pamphlet distributed after the attack, Hamas said it had used 1.5 tons of explosives and had recorded video of the incident.
Palestinians have used tunnels in the area to smuggle weapons from Egypt. Israel has carried out operations to crack down on the smuggling.
Shell explosion in schoolyard
An Israeli tank shell exploded in a Gaza schoolyard Sunday morning, wounding eight Palestinian schoolchildren, Palestinian medical and security sources said.
The children between the ages of 6 and 12 -- sustained moderate to light injuries, the sources said.
The violence happened in Khan Yunis in central Gaza
Israeli military sources said that forces in the area identified what they thought was a number of mortar shells being fired towards Israeli settlements nearby.
In response, the forces fired towards the positions with light weapons, but did not fire a tank shell, the military sources said.