Iyad al-Bozzom, spokesman of Hamas-run Ministry of Interior, told Xinhua that the security services' investigation into the two explosions made a progress and some suspects have been arrested.

Al-Bozzom didn't give further details, but he stressed on continuing state of alert and intensive investigations to uncover the circumstances of the explosions.

Three security officers were killed and two others wounded in two bomb attacks on two police checkpoints west of Gaza on Tuesday night.

The security services have intensified their deployment in different areas of the Gaza Strip, especially on the main roads and set up checkpoints.

Palestinian factions in the Gaza Strip condemned, in separate statements, the bombings as criminal acts.