A suicide car bomber killed nine people in an attack on a military airport in eastern Afghanistan on Monday,officials said,the latest bloodshed since copies of the Quran were burned at a NATO base last week. The Taliban claimed responsibility for the attack as revenge for the Quran burnings. Nineteen Afghan civilians and law enforcement officers and four NATO soldiers were wounded in the blast,a spokesman for the NATO-led International Security Assistance Force (ISAF) in Nangarhar province,of which Jalalabad is the capital,said. Jalalabad airport is almost exclusively used by NATO and the US military. Anti-Western fury has deepened significantly since the desecration of the Muslim holy book at the main NATO Bagram air base in Afghanistan. NATO described the incident as a tragic blunder. The US Embassy warned of a heightened threat to American citizens in Afghanistan and many Westerners are on lock down,meaning they are not allowed out of their fortified compounds. Riots have raged across Afghanistan over the past week despite widespread apologies from US leaders,including President Barack Obama and military commanders. Seven US military trainers were wounded on Sunday when a grenade was thrown at their base in Afghanistans north. Chants of Death to America! have come to characterise the protests and some demonstrators have hoisted the white Taliban flag. With few signs of the crisis abating,the US ambassador said the United States should resist the urge to pull troops out of Afghanistan ahead of schedule. Tensions are running very high here. I think we need to let things calm down,return to a more normal atmosphere,and then get on with business, Ambassador Ryan Crocker told CNN. This is not the time to decide that we are done here. We have got to redouble our efforts. Weve got to create a situation that al-Qaeda is not coming back, he said. Under an international agreement,foreign combat forces are due to leave Afghanistan by the end of 2014,a process which is already under way. The groundswell of anger over the burning of the Quran has highlighted the challenges ahead as Western forces try to quell violence and bring about some form of reconciliation with the Taliban. The violence has killed more than 30 people and wounded at least 200,including two US troops shot dead by an Afghan soldier who joined rallies in the east. Two US officers were also shot at close range inside the Interior Ministry. In an interview from Rabat,US Secretary of State Hillary Clinton said the violence was out of hand and it needs to stop.