South Africa's police spokesperson has apologised for remarks made by an officer during the arrest of Muslims who had congregated in a mosque against orders banning gatherings.

The incident, on Saturday in the Mpumalanga province in the north of the country, led to the arrest of 24 people, the AFP news agency reports.

It was caught on a video that has been authenticated by the authorities, according to AFP. One of the police is heard saying "Are you bigger than the president? Is Mohammed bigger than the president?".

Brigadier Vishnu Naidoo said in a statement that the comments made by the officer were "rather unfortunate".

He said it was "unacceptable that someone could make such an utterance".

The spokesperson said investigations into the matter had started and the officer who made the remarks will be "brought to book".

But police still warned that those found congregating will be arrested and charged for defying rule against social gathering.

South Africa's President Cyril Ramaphosa asked Muslims to pray at home during the month of Ramadan to prevent the spread of coronavirus.