At least 28 students and one teacher killed in incident at Al-Khair Education Center, a private school in Peshawar.

The roof of a school in northwestern Pakistan has collapsed, killing at least 28 students and a teacher and injuring more than 20 others, a hospital spokesman said.

Rescuers are searching for survivors following the incident on Thursday at Al-Khair Education Center, a private school in Peshawar, the capital of Khyber Pakhtunkhwa province.

A hospital spokesman, Mohammad Asim, confirmed the casualties, saying some of the injured were in critical condition. All the children killed or injured were age 13 or younger, he said.

Lady Reading Hospital has declared an emergency as medical staff treat the wounded.

Reporting from Islamabad, Al Jazeera’s Kamal Hyder said rescue efforts have been complicated because the school is located in a congested area.

“Some of the heavy machinery, which would have been important, could not reach that location. Locals as well as the rescue teams [have] been using buckets and utensils to remove the debris and try to recover those buried under it. This particular school has about 350 registered students,” Hyder said.

“The casualties are likely to rise. Also, dozens of wounded students are in hospital. Some of them are in a serious condition.”

Authorities said an investigation had been ordered to determine the ⁠cause of the collapse.

“Our children are our most precious asset, and every such loss is a tragedy for the entire country. My heartfelt condolences and prayers are with the bereaved families,” Pakistani Deputy Prime Minister Ishaq Dar said in a post on X.

“The prime minister and the government have taken serious note of the situation. Ensuring the safety and protection of our children must remain paramount,” he added.