"We understand six men were taken into a square ... and were executed in front of crowds," the channel quoted own correspondent in Gaza as saying.
Witnesses said the six victims were pulled out of a vehicle, forced to lie face down and then shot dead.
Five bodies were laid in a pile while the mob spat on them. A sixth body was tied to a motorcycle and dragged along the city streets.
In a sign left nearby, the Hamas military wing Izz ad-Din al-Qassam Brigades claimed responsibility for the executions.
Israel has a net of informants in Gaza to identify possible airstrike targets during its seven-day Operation Pillar of Defense. Palestinian Authority's UN envoy, Riyad Mansour, said the death toll from Israeli strikes stood at more than 140, while some 1,000 were injured, AFP reported on Wednesday. Four Israelis were killed by Palestinian rockets since the beginning of the conflict.