Armed men holding dozens of Nigerian hostages at an oil installation in southern Nigeria have demanded a ransom of more than $75,000 (euro58,000) for their release, a police official said on Thursday.
Forty-eight Nigerian employees of Agip, a subsidiary of Italian oil giant Eni SpA, have been held since Monday, when armed protesters overran and shut down Agip's Tebidaba oil pumping station, shutting off around 50,000 barrels of crude production per day.
"Negotiations are still going on. But these people are always asking for money," said Hafiz Ringim, the police commissioner for Bayelsa state.
"Most of these hostage takings are just about money."
A Rome-based spokesman for the company, who declined to be named, said he had no news of a ransom demand. He said 48 people were being held hostage.
He said the closure was a security precaution and the company had no news on whether the facility had been damaged.
Kidnapping is increasingly common in oil-rich Nigeria, where the majority of people continue to live in abject poverty despite tens of billions of dollars made by the government in oil revenues every year.
More than 60 foreigners have been taken hostage so far this year, along with many more Nigerians.
The kidnappings usually end peacefully, although one Nigerian hostage was shot dead in August during a botched rescue attempt.
In a separate incident on Tuesday, an American and a Briton working for a Norwegian oil services company were freed after spending five nights in captivity.
Their captors had demanded a hospital and erosion protection for their community. Nigeria is Africa's largest oil exporter and the fifth-largest supplier of crude to the United States.