A bomb and gun attack on a hydroelectric power station in Russia's Kabardino-Balkaria region has killed two guards and injured two others.

俄罗斯卡巴尔达-巴尔卡里亚地区一座水电站遭受炸弹与枪支袭击，两名守卫死亡、另有两人受伤。

Four bombs caused a fire in the Baksan plant's engine room which was later extinguished（熄灭） , prosecutors¹ said.

Supplies to the electricity grid² were not affected³, according to the state-run RusHydro company.

The plant on the Baksan river lies in a part of the North Caucasus gripped by a violent Islamist insurgency⁴（叛乱，暴动） .

Officials said the flow of water from the dam had been stopped to prevent any flooding downriver.

Kabardino-Balkaria has seen less militant⁵ violence than the nearby regions of Chechnya, Dagestan and Ingushetia.

The most serious attack came in October 2005 when dozens of men stormed the regional capital Nalchik, leaving 136 people dead including 91 militants⁶, according to the Russian government.

'No disaster threat'

RusHydro said in a statement on its website that explosions had hit the plant at 0525 local time (0125 GMT) on Wednesday.

The attackers detonated（引爆，爆炸） four explosive devices in the 25-megawatt Baksan plant while a fifth failed to go off, prosecutors said.

According to police spokesman Adlan Kakakuyev, two cars carrying half a dozen assailants（攻击者） had attacked the plant, shooting two guards and wounding three other people.

The attackers reportedly seized two Kalashnikov assault rifles（突击步枪，冲锋枪） from the dead guards.

The same group are believed to have earlier opened fire on a police station in the town of Baksan.

No group was saying immediately that it had carried out the attack, the agency adds.

The Baksan hydroelectric power station（水电站） was built in the 1930s.

"There is no danger of a technical accident or disaster," regional official Gennady Vykhristyuk said in televised remarks.

"The power plant's staff are alive and well."

According to Russia's Ria-Novosti news agency, Russian Prime Minister Vladimir Putin has put Deputy Prime Minister Igor Sechin in charge of repairing the damaged power station.