At least four people were killed and 35 others injured when twin blasts hit Russia's Dagestan republic, local law enforcement authorities said Monday.

Two car bombs were detonated one after another near the court bailiffs service headquarters in Makhachkala, the capital city of the Dagestan republic, the authorities said, adding the majority of the casualties are police officers who have arrived at the site of the first blast.

Thirty-five people, including one child, have been hospitalized. No children were killed in the blasts, the Health Ministry said on its website.

Also, over 20 cars at a parking lot of the court marshals' office were reportedly damaged in the blasts.

Local police have stepped up security in the Dagestan's second largest city of Kaspiisk before the soccer game due there Monday evening.

Dagestan, a Northern Caucasian republic, has been an arena of the frequent terror attacks and violence against government officials.