Colombo: At least 19 people were killed and more than 100 others injured after violent clashes erupted inside a prison in Negombo, Sri Lanka, authorities said.

According to international media reports, fighting broke out between two groups of inmates at the Negombo Prison on Sunday. Although prison officials managed to bring the situation under control later that night, violence flared up again on Monday, leading to further casualties.

The unrest resulted in the deaths of 19 people, including 15 inmates and four prison staff members, while more than 100 prisoners were injured.

The injured were taken to hospitals in Negombo for treatment, while those in critical condition were being transferred to medical facilities in the capital, Colombo.

Sri Lankan authorities have launched an investigation to determine the cause of the prison violence and the circumstances that led to the deadly confrontation.

Officials have not yet released further details regarding the identities of those involved or the motive behind the clashes.