GAZA - Israeli planes carried out strikes on tunnels used for smuggling along the Gaza-Egypt border and a building east of Gaza city on Saturday, causing damage but no casualties, security forces and the Israeli military said.

An Israeli military spokesman said the operation was in response to the firing of a rocket and a mortar shell into Israel by militants late on Friday. Both landed in open ground.

The aircraft struck two tunnels and a building that housed a munitions workshop. The air strikes are in response to what has become the daily launching of rockets and mortars into Israel, the Israeli army spokesman said.

A Hamas security official also said two tunnels were targeted and the building that was hit was a marble factory. He said there were no casualties.

A day earlier Israel released 20 Palestinian women from prison in exchange for a video recording of an Israeli soldier held by militants in Gaza.

The exchange with Hamas Islamists who control the Gaza Strip was seen as a step toward a broader Palestinian prisoner release and freedom for the soldier, Gilad Shalit, which are priorities for both sides since his capture in a cross-border raid in June 2006.

(Reporting by Nidal al-Mughrabi in Gaza and Ori Lewis in Jerusalem; Writing by Ori Lewis; Editing by Andrew Dobbie)