The Palestinian Authority condemned on Friday the recent Israeli air strikes against the Gaza Strip, which had so far killed four people and injured 13 others, most of them children and some in critical condition, according to medical sources, as WAFA reported. Members of the PLO Executive Committee Saeb Erekat told Voice of Palestine radio that Israel wants to sabotage the calm that prevails in the region and Palestinian reconciliation efforts. He said Israel is not happy with the calm that prevails on the Gaza borders with Israel. He accused the Israeli government of seeking to end the calm through an escalation not only on the Gaza Strip, but also through an increase in settlement construction, closing the Magharbi Gate in the Old City of Jerusalem, and burning mosques. Medical sources in Gaza said an Israeli air strike early Friday on northern Gaza killed a Palestinian man and critically injured his wife and two children when their house collapsed. It said Bahjat Za'lan, 38, was killed and 13 others were injured in the air strike, including seven children and two women, all from the same family. An Israel air strike on Thursday killed two Palestinian members of Hamas and Fatah and injured four people, including children, while another air strike on Wednesday killed a member of the Islamic Jihad. The Thursday strike prompted retaliation from the armed groups in the Gaza Strip, who fired a number of missiles at southern Israeli towns, without causing any damage or injury.