Israeli airplanes carried out two air strikes in the Gaza Strip around midnight on Thursday, witnesses said.

One of the raids targeted a smuggling tunnel beneath Gaza's southern border with Egypt and destroyed the tunnel, the witnesses said, adding that houses near the borders were slightly damaged in the bombing.

The other air strike hit an open space in the east of Gaza city.

There have been no reports of casualties in the two aerial attacks.

The Israeli attacks came after Palestinian militants fired four missiles into southern Israel over the past 24 hours.

No Palestinian groups have claimed responsibility for the rocket fire, which renewed three months after Gaza's Hamas rulers persuaded militant factions to halt attacks following a few days of cross-border violence that left 19 Palestinians dead.