(CNN) -- The number of wounded from a suicide bombing late Friday in the Russian republic of Dagestan reached at least 30 on Saturday, state media reported.
The blast occurred during an "anti-terrorist operation" in an area blocked off by police in the Dagestani capital of Makhachkala, a local law enforcement source told the official RIA-Novosti news agency.
Twenty of the 30 people hospitalized are police officers, RIA-Novosti reported.
"The terrorist attempted to break through a police cordon, but he was stopped by a policeman and set off the bomb. His identity is being established," the police source said.
Earlier Friday evening, police had surrounded a group of militants in a private house in Makhachkala. Two militants and two police officers were killed in the ensuing gunfight, according to RIA-Novosti.
In recent years, the republic has faced ethnic friction, spillover from the discord in neighboring Chechnya and attacks on government officials by militant Islamists, the International Crisis Group has said.