A double airstrike last night on Gaza was Israel's swift response to four mortar attacks on the neighbouring Kfar Aza collective farm which killed an Israeli man and wounded three during the day.
Five Hamas security men were killed in the airstrikes on the southern Gaza towns of Khan Younis and Rafah.
The mortar attacks led to the first Israeli fatality since a death in late February triggered days of military action against Hamas-controlled Gaza when troops, armour and air power swept in to target militants. 120 Palestinians died, many of them civilians.
The Israeli army says nearly 2000 rockets and mortars have been fired from Gaza into Israel this year. Previously short range and inaccurate, their range and accuracy is improving. In the last six years of cross-border attacks from Gaza, 10 Israelis have been killed. Israel frequently mounts operations into Gaza to try and stop the attacks. .