An explosion tore through a police post in the southern Russian region of Dagestan (search) Tuesday, killing at least one officer and wounding three, a regional police spokeswoman said.

The blast took place in Makhachkala (search), the capital of Dagestan, said Marina Riasulova, a spokeswoman for the regional Interior Ministry.

Dagestan borders Chechnya (search), where separatist rebels have been fighting Russian forces since 1999, and violence that some believe is connected with the Chechen insurgency is increasing in the republic.

Ten police troops died Friday in Makhachkala when their truck was blown up outside a public bathhouse.

Earlier Tuesday, engineers defused a powerful explosive device found near a theater in Makhachkala. On Monday, a regional lawmaker was found shot dead in his Mercedes in a western part of the province.