Suicide bombers believed to be in line with the Islamic State (IS) group have attacked two police checkpoints in Gaza and killed three Palestinian officers, according to security sources.
against militants affiliated to the IS.
One of the bombers who carried out the attacks on Tuesday had previously been detained, BBC security sources said.
After the attacks with emergency forces the state of emergency was declared.
Two policemen were killed and a third Palestinian injured in the first bomb fired from a motorcycle near a police checkpoint.
The second explosion, less than an hour later, killed another policeman and wounded several people at a stop-off separate checkpoint, Hamas Interior Ministry said.
- Palestinian Territory Profile
Security forces deployed hundreds of workers on the main streets of the Gaza Strip after the attacks.
Hamas periodically faced internal resistance from more die-hard Islamist militants ̵
Hamas seized control of Gaza from Palestinian Authority President Mahmoud Abbas during a civil war in 2007.