At least 10 people have been killed in a shoot-out between jailed militant Islamists and security officers at a prison in Somalia, government spokesman Ismail Mukhtar has said.
The al-Shabab militants had attempted to escape from the heavily guarded prison in the capital, Mogadishu.
An investigation is under way into how the militants obtained weapons.
Some reports suggested that an inmate managed to disarm a warden and then a group of them raided the armoury.
The BBC’s Bella Sheegow in Mogadishu says Monday’s incident is highly embarrassing for the government as the prison, the second biggest in Somalia, is guarded by elite forces.
The attack was repelled after reinforcements were called in.
The most dangerous al-Shabab militants are kept in the prison, including those serving life sentences or awaiting execution after being sentenced to death.
Inmates had also attempted to break out of the prison in 2017, and the government was under pressure to prevent further such incidents, our reporter adds.
We will not leave anything to chance. The government is investigating how this happened and who was responsible for what happened as well as who facilitated the inmates to get the weapons,” Acting Justice Minister Hassan Hussein Haji said.
Mr Mukhtar said none of the prisoners had managed to escape.
He said four militants were killed in the shoot-out.
He did not give details on who the other six were, except to say that the prison guards had also suffered casualties.
Al-Shabab, which is linked to al-Qaeda, has been waging a brutal insurgency in Somalia for more than a decade.
It has been pushed out of Mogadishu by government and African Union troops, but the group still carries out bombings and assassinations in the city.