Lagos: An explosion and gunshots sent crowds running at a campaign rally in southern Nigeria`s Rivers state on Tuesday, in the latest unrest before polls next month.
The violence erupted at the All Progressives Congress (APC) meeting of governorship candidate Dakuku Peterside in Okrika, the hometown of President Goodluck Jonathan`s wife Patience.
Political tension has raged in Rivers since outgoing governor Rotimi Amaechi defected to the APC from the ruling Peoples Democratic Party (PDP) in 2013.
The war of words has been particularly fierce between Amaechi`s camp and supporters of the first lady.
Critics have alleged that she sees Rivers as her personal political domain and was committed to removing the governor at any cost.
Peterside, who is Amaechi`s hand-picked successor, had tried twice previously to hold a rally in Okrika but was forced to cancel on security grounds.
As supporters were gathering for Tuesday`s rally at the National Secondary School, a small explosive device went off, forcing crowds to scatter but causing no casualties, a witness said.
Organisers then decided to press on with the event but gunshots from unknown assailants caused a second wave of chaos, live pictures broadcast on the Channels television station showed.
A reporter from the privately owned TV channel was forced to take cover, lying with his stomach on the ground as armed security personnel moved in the background.
Police were not immediately available to comment on the identities of the gunmen.
"We have been attacked," Amaechi`s spokeswoman Ibim Semenitari told AFP, declining further comment.The National Human Rights Commission last week said 58 people had been killed in political violence in the run up to Nigeria`s polls, which were initially scheduled for February 14.
The commission pointed to oil-producing Rivers in the Niger Delta as a flashpoint area for potential unrest, in part because of the bitter rivalry between the APC and the first family in the state.
In the national campaign, President Goodluck Jonathan is facing a tough test against the APC`s Muhammadu Buhari, a former military ruler.
Rivers has been identified as a key swing state.
Jonathan comes from neighbouring Bayelsa and had previously banked on massive support across the Niger Delta but Amaechi`s defection to the APC has changed the political dynamics.
Losing Rivers could ruin Jonathan`s re-election hopes and would likely be seen as a personal embarrassment to the first lady, who is an often criticised figure in Nigeria.
Patience Jonathan had initially suggested that the kidnapping of more than 200 schoolgirls in Chibok by Boko Haram in April last year was staged to embarrass her husband.
Later, while meeting with relatives of the hostages, she appeared to fall into a religiously inspired trance, repeatedly shouting "there is God-o!", a video of which went viral in Nigeria.