An explosion at a mosque in eastern Afghanistan has killed 62 worshippers and wounded dozens of people gathered for Friday prayers.

Provincial officials say the blast, which caused the mosque’s roof to collapse, underscored the record-high number of civilians dying in the country’s 18-year war.

Attahullah Khogyani, spokesman for the governor of Nangarhar Province, said the militant attack wounded 36 others.

He said it was not immediately clear if the mosque was attacked by a suicide bomber or by some other type of bombing.

“Both men and children are among those killed and wounded in the attack,” he said.

Sediq Sediqqi, spokesman for Afghan President Ashraf Ghani, strongly condemned the attack on his official Twitter account.

“The Afghan government strongly condemns today’s suicide attack in a mosque in Nangarhar province,” he tweeted.

“The Taliban and their partners heinous crimes continue to target civilians in time of worship,” he added.

No one immediately claimed responsibility for the attack, but both the Taliban and the Islamic State group are active in eastern Afghanistan, especially Nangarhar province.

However, Zabihullah Mujahid, the Taliban’s spokesman in a statement condemned the attack in Nangarhar and called it a serious crime.

Zahir Adil, spokesman for the public health department in Nangarhar Province, said 23 of the wounded were transferred to Jalalabad, the provincial capital, and the rest were being treated in the Haskamena district clinic.

The spokesman for UN Secretary-General Antonio Guterres said leader “strongly” condemned the attack and said those responsible must be held accountable.

Amnesty International’s deputy South Asia director, Omar Waraich, said the attack “demands the world’s attention”.

“Flagrant violations of international humanitarian law such as deliberate targeting of civilians are not something anyone should get used to or learn to ignore,” he said.

The violence comes a day after a United Nations report said that Afghan civilians are dying in record numbers in the country’s increasingly brutal war, noting that more civilians died in July than in any previous one-month period since the UN began keeping statistics.

“Civilian casualties at record-high levels clearly show the need for all parties concerned to pay much more attention to protecting the civilian population, including through a review of conduct during combat operations,” said Tadamichi Yamamoto, the UN secretary-general’s special representative for Afghanistan.

Efforts to restart talks to end Afghanistan’s 18-year war picked up earlier this month, just weeks after US President Donald Trump last month declared the talks “dead,” blaming a surge in violence by the Taliban that included the killing of a US soldier.

– AAP