At least 16 people have been killed in southern Afghanistan when security forces tried to dispose of a container full of explosives in the city of Kandahar, officials said.
Nematullah Barak, head of Mirwais hospital in Kandahar, said the latest figures "show 16 dead and 38 wounded people brought to the hospital".
"We still have two ambulances at the site because there might be more people under the rubble," he told AFP news agency.
Four security officers were among the 16 killed in the blast in Kandahar. (Photo: Ahmad Nadeem/Reuters)
Daud Ahmadi, spokesman for the provincial governor, confirmed the death toll and said four security forces were among those killed.
At least five small children were wounded in the explosion, he said.
Dozens of shops and nearby homes were destroyed or damaged, and the death toll could rise, he said.
Abdul Saleh, 29, who was wounded in the blast, said the sound was "so loud, like strong thunder".
He told The Associated Press that he was knocked unconscious and later woke up in a hospital bed.
There was some confusion about the cause of the explosion, which sent a huge cloud of dust and smoke into the air.
Officials initially said it was caused by a bomb packed into a minibus but later said the explosives were in two containers stored in an area of mechanics workshops.
No group immediately claimed responsibility.
The blast was quickly condemned by President Ashraf Ghani, who praised the "brave" officers who dealt with it.
Elsewhere in Afghanistan, the Taliban launched a wave of attacks late on Monday in the eastern Ghazni province, killing at least 14 police, including a district police chief and a reserve unit's commander, according to provincial council member Hassan Reza Yusoufi.
Hundreds of people have been killed in high-profile attacks carried out by the Taliban and Islamic State of Iraq and the Levant (ISIL, also known as ISIS) group since the beginning of this year.
At least 11 Afghan schoolchildren were killed in Kandahar province last month when a suicide car bomber hit a convoy of Romanian troops patrolling the area as part of the US-led NATO forces.
In one of the deadliest attacks, at least 29 people, including nine journalists, were killed after two explosions claimed by the ISIL hit the capital, Kabul, last month.
An increase in attacks has been observed ahead of the long-delayed parliamentary and district council elections scheduled for October 20.