Taliban bombers have attacked an Afghan police convoy outside the capital Kabul, killing at least 30 people and wounding 50 others, officials say.
Two bombs hit a convoy of buses carrying graduates from a ceremony on the city’s western outskirts.
Paghman District Governor Musa Khan told the BBC that all but two of the dead were police cadets.
The bombing was claimed by the Taliban and follows an attack on a bus just over a week ago that killed 14 people.
A Taliban spokesman said that in Thursday’s attack, the first bomber attacked one bus and when rescuers began to arrive the second drove an explosives-laden car into their vehicles.
Officials are still trying to confirm the precise number of dead but witnesses describe a scene of carnage.
Kabul’s police chief is at the scene of the attack, about 20km (12.5 miles) west of the capital.
The cadets were returning to Kabul from a training centre in Wardak province and were about to go on leave.
BBC diplomatic correspondent Jonathan Marcus says the latest violence in Afghanistan – just a few days ahead of a Nato summit in the Polish capital Warsaw – underscores the need for a continued Western engagement in Afghanistan where local security forces are having only limited success in restoring order.
The US and Nato combat mission in Afghanistan ended in December 2014.
US forces have taken on an advisory role since then, while also carrying out counterterrorism missions against so-called Islamic State and remnants of al-Qaeda.
Recent Taliban attacks
- 19 June: At least 14 Nepali security guards killed in suicide attack on minibus in Kabul
- 5 June: Afghan lawmaker and at least three other people killed by a bomb in Kabul.
- 25 May: 25 people killed in Kabul, including employees in judiciary
- 19 April: At least 64 people killed in explosion in Kabul
- 11 April: At least 12 police recruits killed on bus near Jalalabad
- 27 Feb: Suicide bomber kills 15 people near the Afghan defence ministry in Kabul
- 28 Jan: Afghan police officer drugs and kills 10 colleagues