MOSCOW (AFP) - A suicide bombing at a military installation in Russia's volatile North Caucasus region of Dagestan killed five people Sunday and wounded 39, Ria Novosti news agency said, citing a top security source.

A suicide bomber attacked a base used by a special military motorcycle squad at Dalny near the city of Buynaksk, the source said, adding: "According to preliminary information, it claimed five lives and wounded 39."

However, Russia's defence ministry put the death toll at three and said 36 people had been wounded.

"The attack occurred at 00:30 am (2030 GMT Saturday)," the ministry spokesman told Interfax news agency.

A second explosion took place at a highway nearby, but there were no casualties, Ria Novosti said.

Shootings and bomb attacks have become a near-daily occurrence in the North Caucasus, particularly in Dagestan and its capital Makhachkala, where the authorities are battling an increasingly deadly Islamist insurgency.

Analysts say poverty and corruption create a fertile ground for violence and help Islamist militants recruit young people in the region.

In 1999, a suicide bombing in Buinaksk killed 68 and injured more than 100.