A commander affiliated with Palestinian Authority Chairman Mahmoud Abbas's Fatah movement was shot dead on Sunday, in the most serious attack since Abbas launched a new security plan aimed at calming a wave of violence in the Gaza Strip last week. Fatah quickly blamed militants from the rival Hamas group, with whom it shares power in the Palestinian government. There was no immediate comment from Hamas. The dead man was identified as 32-year-old Baha Abu Jarad of the Al Aksa Martyrs' Brigades. He was shot while driving through the northern Gaza town of Beit Lahiya, and later died of his wounds, hospital officials said. "This is a cowardly assassination attempt carried out by the enemy of our people and suspicious criminals who want to blow up the Palestinian internal arena," a spokesman for Al Aqsa said before Abu Jarad died. "We are not going to hesitate to pursue the criminals behind this shooting and punish them," he added. Fatah issued a statement accusing Hamas of carrying out the shooting. Since Israel withdrew from Gaza in 2005, the area has experienced a wave of infighting, armed robberies, deadly family feuds and kidnappings. Hamas and Fatah formed their unity government in March with the aim of restoring calm. The alliance has brought a lull in factional fighting, but crime and violence remain rampant in Gaza. However, in recent days, factional tensions have heated up after Abbas ordered 3,000 police to fan out across lawless Gaza City on Thursday without coordinating the deployment with Hamas. The latest round of violence has been the fiercest since Hamas and Fatah teamed up to share power.