Gunmen killed several supporters of a politician in Nigeria's oil-producing Niger Delta on Friday during a gathering at his home, the latest act of political violence ahead of elections in April.
Supporters of Timi Alaibe, who quit as presidential adviser on the Niger Delta last month to run for the governorship of Bayelsa state, were attacked during a reception to welcome him back from the capital Abuja, witnesses said.
"When we arrived for the reception, we started hearing gunshots and vehicles being damaged, and the gunmen kept advancing towards the crowd," one eye-witness said, asking not to be named for fear of reprisals.
Initial reports said two people were killed by attackers armed with guns and machetes, but witnesses later said they believed four people died and two were critically injured.
"I can confirm there were some skirmishes at his home in Opokuma this evening. It's an attack we're still investigating," Bayelsa state police spokesman Eguavoen Emokpae said.
Africa's most populous nation has been rocked by pockets of violence around the country in recent weeks and there are fears of further unrest as it prepares for presidential, parliamentary and state government elections in April.
The Niger Delta, home to the continent's biggest oil and gas industry, is a potential flashpoint and Bayelsa -President Goodluck Jonathan's home state- is particularly volatile.
Two bombs exploded during a political rally there just over a week ago.