A suicide bomber injured at least 30 people on Friday evening during an anti-terrorist operation in the Dagestani capital of Makhachkala, a local police source said.
Earlier reports said only four police officers were injured as an unknown person blew himself up in the area cordoned by police.
"According to latest updates, 30 people, including 20 police officers, have been hospitalized after the blast," the source said, adding that three people were in serious condition.
"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 official said.
Police surrounded a group of militants in a private house in Makhachkala on Friday evening. Two militants and two police officers were killed in the ensuing gunfight.
The special anti-terrorist operation has been suspended until Saturday morning as an unknown number of militants remain holed up in the surrounded building.
MAKHACHKALA, September 25 (RIA Novosti)