Three Palestinians and an Israeli were wounded Monday in violence on the Gaza-Israel border, according to officials from both sides.

Israeli military said soldiers opened fire on a group of suspicious Palestinians across the border in northern Gaza. Palestinian Health Ministry official Moaiya Hassanain said two wounded men were brought to hospitals, and the military said another was taken to Israel for treatment.

Later, Palestinians fired two mortar shells from Gaza, Israeli rescue services and the military said, slightly wounding a soldier.

Border incidents between Hamas-ruled Gaza and Israel have been relatively infrequent in recent weeks.

Also Monday, Israeli TV stations broadcast video that appeared to show Hamas forces killing Gaza rebels believed to be part of an extremist group during an armed confrontation earlier this month.

The video of the Aug. 15 clash shows what appears to be black-clad Hamas militants firing at rebels pinned in a mosque courtyard and mowing them down during a fierce exchange of fire. In two scenes, Hamas militants appeared to be executing captives by gunfire at close range.

At least 24 people were killed in the daylong standoff in Rafah on the Gaza-Egypt border. Hamas forces surrounded a stronghold of Jund Ansar Allah, an extremist group that claims inspiration from al-Qaida and charges that the militant Islamic Hamas is too liberal.

In the video, bodies are seen falling to the ground during the gunfire. In one scene, a group of Jund Ansar Allah captives stands motionless against a wall a few feet (meters) away.

Channel 10 and Channel 2 TV said the blurred, jumpy video was taken by cell phone from across the street. Channel 2 said Hamas rival Fatah distributed the video.

Channel 10 also broadcast a recording of what it said was the Hamas military communication channel, ordering Hamas forces to "execute everyone."

There was no immediate comment from Hamas officials.