Israeli fighter jets carried out a series of air raids on the Gaza Strip Friday, as Palestinian militants continued to fire rockets into Israel, security sources said.

Israeli warplanes carried three air raids on a Hamas military site in the city of Rafah and another Hamas site in Khan Younis city, both in southern Gaza Strip, the sources told Xinhua, adding that more airstrikes targeted open space in Rafah and Khan Younis. No casualties have been reported so far.

The air raids came as Gaza militants continued to fire rockets into neighbouring Israeli cities Friday. Israel’s Public Radio reported that six rockets hit Israeli cities, causing no damages or casualties.

Earlier in the day, an Egyptian-brokered truce between Israel and Hamas was restored after bloody days of tit-for-tat violence between the two sides, a Hamas official said.

“Egypt’s intelligence and UN officials have brokered the ceasefire in order to avoid more deterioration,” the Hamas official said, stressing that both Hamas and Israel are not interested in a wider cycle of violence.

Gaza has witnessed an increase in violence since three Israeli teenagers disappeared in the West Bank city of Hebron June 12. Israel accused Hamas of abducting the teens who were found dead near Hebron Monday.

The ongoing violence in the Gaza Strip threatens the validity of the Egypt-brokered ceasefire agreement reached between Israel and Hamas in 2012. The deal ended eight days of large-scale Israeli aerial operation in the coastal enclave, during which about 180 Palestinians and six Israelis were killed.