At least nine people were killed and dozens injured when a mosque they were building in Somalia collapsed.

Over 100 people were helping pour a concrete foundation to the mosque in Garasballey district close to the capital Mogadishu on Friday when the structure suddenly collapsed, leaving several trapped under the debris.

Sheikh Mohamed Hashi, imam of the mosque, said around 30 people were injured.

“Nine bodies were recovered under the collapsed building, some of them have had suffocated to death, others were hit by the falling concrete walls,” said a witness identified as Ali Muhidin.

“I saw several dead bodies that were discovered under the debris, they were had been working on its construction,” said Mohamed Yahye, another resident.

An engineer on the refurbishment project has been arrested on suspicion of negligence, local media reported.

Heavy rains have fallen on the area over the past few days.

The Somali government controls Mogadishu and other cities, but militants from the al-Qaeda-linked group al-Shabab dominate many rural areas.

More than 22,000 African Union soldiers and police are deployed in the country to protect the government.