Peshawar | At least 28 children and a teacher were killed and more than 40 people injured when the roof of a private school collapsed in Peshawar, the capital of Pakistan's Khyber Pakhtunkhwa province, on Thursday, police said.

The incident occurred in Dir Colony in the inner city area, Peshawar Capital City Police chief Mian Saeed said.

The owner of the school has been arrested, he said.

According to Lady Reading Hospital spokesperson Muhammad Asim, 28 students, including six girls, and a lady teacher were killed in the incident.

Over 40 people were also injured, he said.

An emergency was declared at the hospital to treat the injured, Asim said, adding that all the children killed in the incident were aged 13 or younger.

Peshawar Deputy Commissioner Afaq Wazir has ordered a probe into the building collapse.

Rescue teams were clearing the debris and searching for children and school staff who might still be trapped beneath the collapsed structure.

Prime Minister Shehbaz Sharif expressed deep grief over the loss of life in the mishap and extended his condolences to the bereaved families.

He also prayed for the speedy recovery of the injured and directed the authorities concerned that they be provided with the best possible medical treatment.

Governor Faisal Karim Kundi also expressed grief over the roof collapse.