The US military has imposed a curfew on the Iraqi city of Mosul a day after the deadliest attack on Americans since the invasion last year. On Tuesday, a rocket attack on a tented dining hall left over 18 US soldiers dead. An Iraqi militant group, Ansar al-Sunna, claimed responsibility for the attack.The US President admitted it delivered a massive blow to plans to stabilise Iraq before elections next year."The idea of a democracy taking hold in what was a place of tyranny and hatred and destruction is such a hopeful moment in the history of the world," said George Bush. A survey in the United States shows that seven out of 10 people believe the American casualties are getting unacceptable and the pressure seems to be growing on the Bush administration to announce a quicker exit strategy.