Sri Lanka's deputy economic development minister Lakshman Abeywardene said the island's defence secretary has ordered police to take action against all suspects including the local council chief who was present during the incident.
"Nobody has been protected," he said.
He said some suspects had been arrested and the local councilor had given himself up to the police.
Earlier in the year a candidate of a local government poll was killed in a shootout with a fellow candidate.
The family of the dead member has been asking for justice.
Reports said British national, a Red Cross aid worker in Gaza, intervened in a brawl between two rival gangs during a Christmas day party in Tangalle in Southern Sri Lanka. He and his colleague was holidaying in Sri Lanka during the Christmas break.
Minister Abeywardene said he and Sri Lanka's envoy to Moscow who is currently in Colombo had me the Russian national who is now in hospital, and her medical expenses are being borne by the tourist promoti