The first bomb exploded near a cafe in Kosovska Mitrovica's Serb-dominated northern part around midday on Friday. The town has been divided since the NATO bombings of 1999 into Albanian and Serb sectors.
The second explosion occurred after Serb youths set two Albanian shops on fire, as firefighters rushed to the scene a bomb was thrown injuring at least six firefighters.
Tensions have risen in the town, the largest Serbian enclave in Kosovo, after a Serb was stabbed during street clashes with Albanians on December 30.
Police arrested two Albanians in connection with the assault, which led to reprisals by Serbs who set shops on fire and torched Albanian-owned cars.
Serbia has refused to recognize Kosovo as an independent state, despite the province's unilateral declaration of independence in February.
NATO troops and the recently-deployed European Union police (EULEX) are reported to have increased patrols and their presence in the area.