A bomb has gone off on a bus in Tel Aviv, injuring at least ten people. An eye witness said that all the windows of the bus were blown out and that the vehicle was completely charred. There were reports of a man seen leaving the bus shortly before the blast and parts of the centre of Tel Aviv has been sealed off as police search for the suspected bomber, and for any further explosive devices. There were reports earlier that a man had been arrested and subsequently released, suggesting that police enquiries continue. A spokesperson for the prime minister confirmed that the explosion was being regarded as a terrorist attack. As news of the attack was broadcast in Gaza, celebratory gunfire broke out and a Hamas spokesperson said that they regarded the bombing as a blessing and a natural response to the massacres in Gaza. View Larger Map The reaction appeared to polarise opinions in Israel where several passers by this morning told our correspondent that celebrating civilian deaths was wrong and proved that Israel should continue military action until Hamas was unable to launch rockets into Israel. The bomb attack on a bus threatens to complicate ceasefire negotiations taking place in the West Bank and Egypt. UN leader Ban Ki Moon condemned the latest violence and called for peace.