Militant patrols creeks of the Niger Delta area of Nigeria (File photo)

Militants who invaded an oil flow station in Southern Nigeria early last week are still holding oil workers and guards captive. The armed youths have issued demands that include a quarter of a million dollars ransom.

Militants from the Agbaibiri community in the Niger Delta invaded the oil pumping station late Tuesday, seizing at least eight soldiers and 16 workers, forcing the facility to shut down.

Bayelsa State Police Commissioner Hafiz Ringim says the hostage takers are making ransom demands of about $250,000.

"The soldiers, oil workers and the kidnappers are still at the Agip flow station. You are aware that they are demanding for 30 million [Naira], and a couple of other things," said Ringim. "It is one of the those things that you cannot do too much about."

The police chief said he was optimistic that the hostages would be released unharmed, particularly because of the ransom demand.

State officials have held at least two meetings with the militants without achieving a breakthrough. The leader of the government negotiating team said the hostages are in good condition and are being treated fairly well.

Earlier reports suggested about 40 people; including sub contractors, security, and catering staff were at the flow station when it was taken over.

Pumping station owner Agip says the attackers are demanding payment for a boat seized from them by the Nigerian navy.

The local Agbainbiri community is also asking for jobs, the clearing of an oil spill, and the construction of an erosion control facility.

The attack has disrupted 35,000 barrels per day of crude oil. Recent militant attacks on oil facilities in the Niger Delta have reduced Nigeria's oil production by 700,000 barrels per day.