A 45-year-old Nigerian man was being treated at a hospital in the western port city of Patra on Tuesday after being stabbed in the leg during a brawl between a group of inmates in the exercise yard of Aghios Stefanos Prison on Monday evening.

Prison authorities are investigating how the inmates got their hands on several makeshift knives that were used in the fight, which resulted in four Nigerians and one Somali being injured, though only one of the Nigerians was kept for further treatment by hospital doctors.

The cause of the altercation was not known.