Israeli warplanes struck three training facilities in the Gaza Strip early Thursday after rockets were fired into Israel from the coastal enclave, witnesses and security officials said.
An Israeli jet fired a missile into a section of northwest Gaza City, residents in the area said, while explosions were also reported elsewhere in the strip. Fire brigades and ambulances rushed to the targeted areas, but no casualties were immediately reported.
Police and security forces in the coastal area, which is ruled by the Islamic militant group Hamas, had evacuated buildings and security headquarters in anticipation of an Israeli attack after the rocket fire.
Security officials said several missiles were fired at a training facility that belongs to Hamas' armed wing, the Izzidin al-Qassam Brigade, and to Islamic Jihad, another militant group.
Israeli officials, who hold Hamas responsible for attacks from the coastal enclave, had reported that two rockets were fired into southern Israel near Ashkelon and Netivot on Wednesday evening, causing no damage, deaths or injuries.
The Israel Defense Forces released a statement Thursday saying it had struck three infrastructure sites linked to militants in response to the rocket attack.
"The IDF will act against the aggression, will act against those that wish to terrorize Israel and will act to protect Israelis in the line of indiscriminate Gaza rocket fire," said Lt. Col. Peter Lerner, a military spokesman.
A militant Islamist Salafist group affiliated with Islamic State posted a statement on Twitter claiming responsibility for the rocket fire. The group, which calls itself the Omar Brigades, said its attack was in retaliation for the killing of an Islamic State supporter in a shootout a day earlier with Hamas.
It is the second time in a week that the Salafist group had been accused of firing rockets into Israel. Last week, Israeli warplanes carried out six airstrikes on Hamas and Islamic Jihad military facilities in response to rocket fire.
On Tuesday, the Salafist group claimed responsibility for the earlier rocket attack and said in a video that it is not committed to any truce with Israel.
The group also gave Hamas 48 hours to stop the crackdown on its militants and to return weapons Hamas authorities had confiscated from them.
The airstrikes on Gaza last week and Thursday were the most intense since the end of a 50-day Israeli military operation in the Gaza Strip last summer.
Abu Alouf is a special correspondent.