Two car bombs killed at least four people and wounded dozens of others yesterday in one of the bloodiest attacks this year in Dagestan, a turbulent province in Russia’s North Caucasus region where armed groups are waging an Islamist insurgency.

Car bombs, suicide bombings and fire fights are common in Dagestan, at the centre of an insurgency rooted in two post-Soviet wars against separatist rebels in neighbouring Chechnya.

Such attacks are rare in other parts of Russia, but in a separate incident in a suburb of Moscow yesterday, security forces killed two suspected militants alleged to have been plotting an attack in the capital and arrested a third suspect after a gun battle.

One elite police officer was lightly wounded in the exchange of gunfire with the suspects – Russian citizens but trained in Afghanistan or Pakistan – who had holed up in a home in the town of Orekhovo-Zuyevo east of Moscow, authorities said.

Investigators initially said eight people had been killed by the successive blasts in Dagestan’s provincial capital Makhachkala, but law enforcement and health officials later put the death toll at four and said about 40 people were wounded.

The explosions occurred with the space of a few minutes near the headquarters of the court bailiffs’ service and appeared to have been detonated by remote control, said the federal Investigative Committee, a Russian state agency.

Twisted wreckage of a car could be seen near the building, which was cordoned off by police, and black-ened chunks of metal lay in the street.

The Health Ministry said 35 people remained in hospital, including one child, a few hours after the blasts.