Iraqi police forces arrested a number of suspects allegedly connected to the Baquba blasts that killed more than 33, Iraqi TV reported on Thursday.
Baquba was hit by four bomb blasts on Wednesday, including one targeting ambulances carrying the wounded from the two earlier attacks, DPA reported.
The attacks, which left at least 33 people killed and 58 injured, came amid a spike in violence ahead of Iraq's March 7 parliamentary elections.
Baquba, some 60 kilometres north-east of Baghdad, is the capital of Diyala province, which lies on the border with Iran.
The province has been the site of attacks against Iranian pilgrims visiting Iraq, and of an uneasy standoff between Kurdish militias in the north of the province and forces from Iraq's central government in Baghdad.