At least four Palestinians have been killed in an attack in the central Gaza Strip.
A Palestinian group named three people in the car and said they were militants.
One Israeli security source said the blast appeared to have happened when explosives being carried in the car blew up prematurely.
Israel seeks US help over barrier ruling
Meanwhile, Israel has asked Washington to prevent any United Nations Security Council resolution after the UN's highest court ruled its West Bank barrier was illegal.
Palestinians hailed the ruling, with Prime Minister Ahmed Qorei calling it 'historic'.
The US earlier criticised the ruling by the International Court of Justice that the barrier is illegal and should be torn down.
The court rejected Israel's arguments that it needed the barrier for self-defence.
Israel has already said it will not accept the ruling.
A State Department spokesman, Richard Boucher, described the decision as inappropriate and said it might be a damaging distraction from the so-called road map peace process.
