Clashes in a Sri Lankan prison have killed at least 25 people, including four guards, and wounded more than 100 in the worst prison riot in more than five years, officials said on Monday.The wounded were rushed to the Negombo hospital, north of the capital Colombo, following overnight clashes between inmates from two drug gangs, police said.Hospital director Pushpa Gamlath said 19 bodies were brought to her state-run health facility, and more than 100 wounded inmates and guards were also admitted.”There are some victims with gunshot injuries,” Gamlath told the AFP news agency by telephone.Fighting began on Sunday evening at Negombo prison, which houses nearly 10,000 inmates, officials said.Police commandos have been called in, but were not deployed inside the prison.Large crowds of relatives of the inmates gathered outside the prison on Monday.Local residents said they heard gunshots, while authorities deployed drones to monitor the situation.”Four guards were killed when they tried to break up the rioting,” a police official told AFP. “The situation got out of hand this morning.”In December 2020, rioting at another prison in Sri Lanka killed 11 inmates and wounded 117 during the height of the COVID-19 pandemic, leading the government to release hundreds of inmates from overcrowded jails.Official data showed that prisons across Sri Lanka held 41,250 inmates as of Sunday, about four times their capacity.