At least three people have been killed in a suicide car bomb attack at Jalalabad airport in eastern Afghanistan, police say.They say several other people were injured when the bomb exploded at the gates of the airport.The Afghan Taliban have said they carried out the attack.Afghanistan has seen days of deadly protests following the burning of Muslim holy books at a US military base near Kabul a week ago.US officials say the books were destroyed inadvertently.All the casualties at the airport appeared to be civilians, said provincial police official Obaidullah Talwar.The airport serves both civilian and international military aircraft.Meanwhile, Afghan authorities are still hunting a 25-year-old Afghan policeman believed to have shot dead two senior Nato officers at the interior ministry in Kabul on Saturday.On Sunday, France and Germany followed the US and Britain in withdrawing civilian staff from Afghan government institutions in the wake of the killings.President Hamid Karzai has appealed for calm amid anger at the burning of copies of the Koran at the Bagram air base.In his televised address on Sunday, Mr Karzai "condemned with the strongest words" the treatment of the Korans but added: "Now that we have shown our feelings it is time to be calm and peaceful."