Palestinian Prime Minister Rami Hamdallah survived an assassination attempt in Gaza on Tuesday, the Palestinian Authority said after an apparent roadside bomb targeted his motorcade. The attack on the Western-backed leader, who is spearheading the Authority's reconciliation efforts with Gaza's dominant group, Hamas, took place as the White House prepared to hold a meeting on the humanitarian situation in the enclave. There was no immediate claim of responsibility for what one Palestinian Authority security official in Gaza said was a roadside bomb. A second device failed to explode, the official said. Six security guards had been wounded, Mr Hamdallah said shortly after the attack. Hamas, which condemned the attack, and the Authority said they viewed the incident as an attempt to prevent implementation of a unity agreement signed in October that has raised hopes of improving economic conditions in the territory of two million people. Minutes after the explosion, the 59-year-old prime minister, apparently unhurt, delivered a speech at the inauguration of an internationally-funded wastewater treatment plant and pledged to continue to pursue Palestinian unity. He said three vehicles had been damaged in the explosion, which blew out the windows of one of them. The blast sent debris hurtling dozens of metres away and left a crater by the roadside. The Authority said it held Hamas responsible for the attack near the northern Gaza town of Beit Hanoun, stopping short of directly accusing the group of carrying out the assault, but suggesting it had failed to provide adequate security. "It was a well planned attempt. They planted explosive devices two metres deep," Mr Hamdallah said later in the West Bank city of Ramallah, where he is based, without pointing a finger at any group. Hamas and the Palestinian Authority led by President Mahmoud Abbas are still divided over how to share administrative power in the Gaza Strip under the Egyptian-brokered unity deal. Hamas seized control of Gaza in 2007 from forces loyal to Mr Abbas. Welcomed back to Ramallah by applause from a crowd of dozens of people, including cabinet ministers, Mr Hamdallah repeated a call to Hamas to hand over control of Gaza's police force and civil emergency services to the Palestinian Authority. "The attack against the government of consensus is an attack against the unity of the Palestinian people," said Nabil Abu Rdainah, a spokesman for Mr Abbas. In a statement, Hamas said the targeting of Mr Hamdallah's motorcade was "part of attempts to damage the security of Gaza and deal a blow to efforts to finalise reconciliation". Hamas-led security forces said they had launched an investigation.