Israeli air strikes on the Gaza Strip killed an Islamic Jihad militant and wounded three other Palestinians on Saturday, Palestinian medics and witnesses said.

Security sources said three raids targeted the city of Khan Yunis, with the first two not causing casualties.

Witnesses said Abed Muhana, 20, a member of the Al-Quds Brigades, armed wing of Islamic Jihad, was killed in the raid. Medics said three other people were wounded.

An Israeli military spokesman said the aircraft targeted "terrorists preparing to fire rockets at Israel."

Palestinian militants later fired a rocket from Khan Yunis towards Israel.

"A rocket was fired from the Gaza Strip towards Ashkelon," an Israeli port city just north of the territory, an Israeli army spokeswoman said.

A military source said one person was lightly wounded.

On Thursday, two Palestinians were killed in an air strike in the northern Gaza Strip. Israel said its air force targeted a "terrorist squad" that had opened fire on troops in a border area.

That strike came after several days of calm in and around Gaza following a spike in violence last weekend when 12 Palestinian militants and an Israeli civilian were killed.

Militant groups say they are observing an Egyptian-brokered truce agreement but have reserved the right to reply to any Israeli fire, while Israel warns of action against any militants poised to fire rockets across the border.