COLOMBO, Sri Lanka — The death toll in Sri Lanka’s prison clash rose Tuesday to 26, including seven prison officials and 19 inmates, while the government announced that three separate investigations into the incident are underway.

The unrest at the prison in Negombo, about 35 kilometers (22 miles) north of the capital, Colombo, started between inmatse on Sunday and turned violent on Monday after the inmates attacked the guards who intervened. Officials said the inmates even tried to break through the main gate, but were stopped.

On Tuesday, Justice Minister Harshana Nanayakkara called it a “tragic incident” and added that another 77 persons — 23 prison officials and 54 inmates — are still being treated in hospitals.

The Minister did not specify the cause of the deaths and the nature of the injuries.

Three different probes are underway into the incident, Nanayakkara told parliament, adding that a committee led by a retired judge is being set up in addition to the police probe and an internal investigation by the prison department.

He said the investigations will look into what led to the clashes, “whether there were any security lapses or the congestion in the prisons caused this, and our responsibility is to prevent such incidents happening again.”

The first clash erupted between two rival gangs connected to the illegal drug trade, Nanayakkara said. Once order was restored on Monday evening, the inmates who led the violence were transferred to other prisons, he said.

On Tuesday, local television channel Hiru showed hundreds of relatives gathered outside the prison and hospital, seeking information about their loved ones. The relatives were crying and pleading for information.

Security around the prison has been heightened with additional army troops and armed tanks also being deployed.

Sri Lankan prisons are highly congested, with more than 39,000 inmates crowded into a system with a total capacity of just 10,000.