Motorcycle-riding Hamas gunman kills suspected Palestinian collaborator

A gunman on a motorbike shot dead a fellow Palestinian near a Gaza hospital on Monday as militants settled scores with those suspected of collaboration with Israel.

Witnesses said the gunman fired three times into the head and chest of a man who fled from detention on Sunday after an Israeli air attack blew up the security complex housing Gaza's main prison.

On Saturday Israel launched the start of a massive offensive against Hamas' Qassam rocket and mortar fire on its southern communities, targeting dozens of buildings belonging to the ruling militant group in the Gaza Strip.

The police stations of Hamas Islamists who control Gaza have been destroyed by Israel's air strikes on Gaza, but armed militants are out on the streets of the city.

Residents said a second suspected collaborator who also fled the prison was shot by relatives of a militant whose death was blamed on Israeli collaborators.