COLOMBO, July 12 -- The Criminal Investigation Department (CID) is preparing to file murder charges against around 200 inmates suspected of involvement in the deadly violence at Negombo Prison last week, as investigations continue into one of the country's worst prison riots in recent years.

The clashes, which erupted on July 5 and 6, claimed the lives of 29 people, including eight prison officers and 21 inmates, while more than 100 others were injured.

Senior police investigators said extensive inquiries have identified 13 organized crime figures, including underworld suspects known as 'Suresh' and 'Booru Moona', as key instigators of the violence.

Deputy Inspector General of Police in charge of the Crime Division, Chandana Kodithuwak...