Taliban militants ambushed a checkpoint in western Afghanistan, killing at least nine policemen, officials said today, in the latest attack on the country's beleaguered security forces. Two other policemen were killed and four wounded by a roadside bomb en route to the checkpoint to provide backup during the hours-long assault that began late Thursday night, Herat provincial governor spokesman Jailani Farhad told AFP. Two armoured Humvees were destroyed in the attack in Shindand district, Farhad said. The Taliban also seized weapons and ammunition during the raid, he added. Shindand district governor Shukrullah Shakir confirmed the casualty figures. He added that the checkpoint was eight kilometres (five miles) from the district centre. The attack comes a day after Taliban fighters raided a district government compound in the southeastern province of Ghazni, killing at least seven people, including the local governor. The Taliban frequently attack Afghan security forces and steal their equipment, eroding morale among poorly-paid police and soldiers. The latest assaults are the deadliest by the Taliban in several weeks and come as the group prepares to launch its annual spring offensive, which marks the beginning of the traditional fighting season. The Taliban are under pressure to take up President Ashraf Ghani's offer of peace talks but so far have not responded directly to the proposal.