Palestinians inspect the damage of a training camp belonging to the Islamist group Hamas after it was hit by an Israeli air strike in the northern Gaza Strip September 19, 2015. REUTERS/Mohammed Salem

GAZA (Reuters) - Israel carried out air strikes in the Gaza Strip on Saturday after Palestinian militants there fired rockets into southern Israel.

The early morning air strikes targeted two training camps belonging to the Islamist group Hamas, causing no injuries, officials and witnesses said.

Gaza militants fired at least two rockets into Israel late on Friday, Israeli military said. One struck the border town of Sderot, damaging a bus but causing no injuries. A second was shot down by a missile defense system, the military said.

A Palestinian group that supports the Islamic State claimed responsibility for one of the rockets fired at Israel. No-one claimed responsibility for the second rocket attack.

The cross-border violence comes as tensions remain high in Jerusalem and the West Bank, where Israeli security forces and Palestinians have clashed over the past week.

In London, U.S. Secretary of State John Kerry urged calm and called on all sides to exercise restraint amid violence in recent days around Jerusalem’s al-Aqsa mosque, a sacred site revered by Muslims as the Noble Sanctuary and by Jews as the Temple Mount.

Kerry said he had spoken to Israeli Prime Minister Benjamin Netanyahu who had made it clear that “he is completely supportive of the status quo and deeply committed to preventing any kind of incident that will incite.”

“All parties need to refrain from incitement and refrain from engaging in activities that put that relationship at risk,” Kerry said following talks with British Foreign Secretary Philip Hammond on conflicts in Syria, Yemen, Libya and Ukraine.