At least 10 people were killed and 23 injured as Afghan Taliban militants attacked a court in Logar province on Sunday, an official said.The killed people included a prosecutor and three militants who infiltrated the court in Pul-e-Alam, Efe news quoted the official as saying.The injured were rushed to hospital, he said.Taliban militant group claimed responsibility for the attack, saying the explosion killed "several judges and prosecutors".The attack was "revenge" for the recent government execution of six insurgents, it said.Instability in Afghanistan has been increasing since the NATO military mission ended in December 2014, with the Taliban making progress in controlling larger areas of the country as well as an increase in frequency and scale of attacks in large cities.