School students are among 30 people who have been killed in a car bombing in eastern Afghanistan on Friday, officials say.
The blast exploded close to a guesthouse where the students were reportedly staying in Pul-e-Alam, the capital of Logar province.
Witnesses described roofs collapsing and victims being trapped under the debris.
It is not clear who was behind the blast.
Afghanistan has seen a surge in violence since US President Joe Biden announced US troops would withdraw by 11 September.
The bomb went off at around 7pm local time, damaging buildings, including a local civilian guesthouse, according to reports from the scene.
Some of those killed were staying in the guesthouse, including high school students in the city to sit university entrance exams, Hasibullah Stanekzai, head of Logar's provincial council, said.
As many as 90 people were injured by the blast, interior ministry spokesman Tariq Arian said.
He said the explosion caused widespread damage in the area, including to a hospital and residential houses.
"The roofs of houses have collapsed and people are trapped under the debris," he said.
"The security forces are trying to rescue those trapped."
Footage circulating online showed a victims being pulled from the rubble. A ward in a nearby hospital appeared to have suffered blast damage.
The car detonated near the home of the former head of the provincial council and not far from a hospital, Didar Lawang, the spokesperson for Logar's governor, told the Reuters news agency.
The British Embassy in Kabul condemned the attack, saying "this senseless violence against civilians must stop".
The blast came a day before the US military formally begins to withdraw its remaining troops from Afghanistan.
Biden announced earlier this month that all American troops will leave Afghanistan by the 20th anniversary of the 11 September 2001 attacks.
That decision angered the Taliban who had signed a deal with previous US President Donald Trump agreeing all troops would leave the country by 1 May if the militants upheld the deal.
The country has seen a rise in militant violence in recent months, including an increase in civilian casualties.
- BBC