Police also said at least 15 were wounded, adding they suspected the Islamist sect known as Boko Haram was behind the attacks on Easter Sunday night at a hotel tavern and transport hub in Maiduguri, as well as a third one on Monday morning.
It was unclear whether the blasts were linked to the unrest that swept across Nigeria's north last week, leaving more than 500 dead according to a local rights group. Analyst fear the violence might keep some voters away from polling stations on Tuesday.
Maiduguri has long been hit by violence blamed on the Islamist sect.
"From our records the death toll has risen to three, which include a police corporal and two civilians who were at the tavern to have some drinks," police commissioner Mike Zuokumor told AFP.
He said in the hotel attack 14 people, including two children playing outside its tavern, were wounded, and an officer was injured in Monday's attack.
"We also had another bomb blast this morning targeting a police team," said Zuokumor, adding that two attackers on a motorbike tossed a home-made bomb at a police patrol van, seriously wounding one policeman.
The explosions at the hotel and transport hub Sunday night occurred nearly simultaneously, with the two locations not far apart. Two blasts hit the hotel and one hit the station for buses and communal taxis.
Police said they suspected the Boko Haram sect in all the attacks.
The sect is seen as opposed to the ruling party in Borno state, where Maiduguri is the capital, and some of the recent violence blamed on the group is believed to have been politically motivated.
Most of Nigeria's 36 states will hold governorship elections on Tuesday, including Borno, where the All Nigeria Peoples Party is in power.
