Dozens of people are feared dead following a clash between rival party supporters near the southern city of Port Harcourt over the weekend.
The levels of political violence in the country are now causing increasing concern, with elections in Nigeria just a few weeks away.
The Delta has seen clashes in recent weeks
Nigeria's oil producing areas have been particularly volatile in recent weeks, with continuing instability in the rivers and creeks of Delta State, forcing the evacuation of major oil facilities and severely disrupting production there.
This latest incident was in neighbouring Rivers State, near one of the key oil industry centres in the south - Port Harcourt.
Hundreds of members of the opposition All-Nigeria People's Party had gathered to hear their local leaders speak.
Accounts vary as to how the violence began, but eyewitnesses from the ANPP say that as they arrived at the venue they were set upon by local youths with machetes and other weapons, forcing people to flee and creating total confusion.
According to the police, scores of people died as the crowd stampeded into a river to escape the disturbances.
Another violent incident, also reported over the weekend, involved members of a group calling for the secession of eastern Nigeria.
The group, the Movement for the Actualisation of the Sovereign State of Biafra (Massob), has been officially banned, but attempted to hold a rally near the eastern town of Owerri on Saturday.
Their route to the venue was blocked by armed police, and in the confusion that followed, the police say at least seven people were shot and killed.
Members of the group say the number of dead was far higher, with hundreds arrested.
It is becoming increasingly evident that there are those within Nigeria who are intent, for whatever reason, on disrupting the election process through violence.
Tensions are so high in some areas that President Olusegun Obasanjo recently held an all-party emergency conference to address the issue.
But this appears to have had little effect, and it is becoming difficult to see how successful elections can be held in areas, particularly in the south and east, where violence and intimidation are increasingly evident.