On Sunday morning missiles fired from Israeli helicopters on targets in the Gaza strip wounded three Palestinians, including a child. According to information from Gaza, the helicopters fired at least 20 missiles on the buildings of an elite police unit, a headquarters of the Fath movement and several facilities in the Khan Unes refugee camp. Israelis say this operation was in retaliation for a mortar attack on the Jewish settlement Kfar Darom in the Gaza strip on the night before. The attack left one Israeli serviceman killed and two wounded. Meanwhile, Palestinians say that Kfar Darom was shelled by activists from the radical Islamic organisation Hamas in revenge for the killing of a Hamas commander, Mahmoud Ab-Hahud. He was killed on Saturday night in a car by a missile from an Israeli helicopter near the Palestinian town of Nablus on the West Bank of the Jordan river. Many observers believe that the recent developments may again sharply worsen Israeli-Palestinian confrontation. It happens on the eve of arrival in the Middle East by two prominent American envoys -- state secretary aide William Berns and new special envoy in the Middle East Anthony Zinni. Their goal is to arrange Israeli-Palestinian dialogue.