MOSCOW -- At least four women were killed and five others were injured in a shooting attack during a celebration of Russia's traditional holiday Maslenitsa in the Russian Republic of Dagestan, regional Interior Ministry said on Sunday.

The incident took place at approximately at 4:30 pm local time (13:30 GMT), when an unidentified gunman armed with a hunting rifle opened fire at a crowd of civilians who were attending a Maslenitsa celebration in the town of Kizlyar in Dagestan, according to the ministry's spokesman.

Three local residents, a police officer and a member of the National Guard were among those injured, a ministry statement said.

The Russian Health Ministry was cited by Interfax news agency as saying that the death toll has risen to five as an injured woman died in the hospital, and another two injured are in critical conditions.

The attacker was killed by the police and National Guard officers, the Interior Ministry said.

According to an Interfax source, there were originally two attackers, a husband and a wife, but the woman had fled before the man started shooting.

The Russian Investigative Committee has launched a criminal investigation into the case.

Maslenitsa is one of Russia's most important religious holidays, which is celebrated during the eighth week before the Orthodox Easter.