The explosions went off at the Labour Party campaign offices in Bayelsa, President Goodluck Jonathan’s home state.
“There was an explosion at the Labour Party office in Ogbia in the night, but I can’t give a specific time. The details are still sketchy and investigations are under way to try to identify the perpetrators,” police spokesman Emokpae Eguavoen told AFP.
Residents said the explosion ocurred around 4:00 am (0300 GMT) and destroyed the office which had been slated for commissioning by Alaibe, hours later.
The party’s campaign chief Thalford Ongolo condemned “the politics of violence”.
Last month attackers targeted his rally as he returned home from the capital Abuja after resigning his post. Several people were killed and scores others wounded.
In November, explosives were used in an attack on his house, but no one was injured.
The state government said the latest explosion was a stunt to attract media attention as well as embarrass President Jonathan, who hails from Bayelsa state.
“They have once again introduced their favorite attention-grabbing technique with the detonation of explosives,” said Bayelsa state spokesman Nathan Egba in a statement.
The Niger Delta is the heart of one of the world’s largest oil industries, but criminal gangs and militants claiming to be fighting for a fairer distribution of oil revenues have carried out scores of attacks in the region.
Nigerians go to the polls in April to elect a president, lawmakers and state governors.