Palestinians in the Gaza Strip fired a rocket at southern Israel this night, the army said, the third such attack in 10 days.
"Gaza terrorists fired a rocket at southern Israel. No injuries reported," military spokesman Lieutenant Colonel Peter Lerner wrote on Twitter.
Local media said it struck open ground south of the city of Ashkelon.
The southern coastal city was the apparent target of three rockets fired late Wednesday, followed a few hours later by Israeli air strikes into Gaza.
On last evening, Israeli media said, the military deployed batteries of its Iron Dome missile defence system around Ashkelon as a precaution.
The army declined to confirm or deny that.
Rocket fire from the strip on May 26 also drew retaliatory air raids.
Nobody was hurt on either side in any of the exchanges.
Local media have said the latest round of rocket fire could be related to infighting between Gaza's Hamas rulers and its opponents.
On Tuesday, Hamas security forces shot dead a Salafist leader in Gaza City during a confrontation as Hamas stepped up measures against militants belonging to Islamic extremist groups, some of whom are known as Salafists.
Since last summer, when Israel and Hamas fought a war in and around Gaza, there have been growing signs of internal unrest between Hamas security forces and extremist splinter groups.
Salafists are Sunni Muslims who promote a strict lifestyle based on that of early "pious ancestors". In Gaza they have made no secret of their disdain for Hamas over its observance of a tacit ceasefire with Israel and its failure to implement Islamic law.
