Lagos: Gunmen kidnapped three senior expatriate management staff and four family members, all Indians, from the residential compund of chemical company Indorama in oil-rich southern Nigeria on Friday, police officers said. "There was an attack on the Indorama residential compound. Three people were taken," Rivers State Police Commissioner Felix Ogbaudu told AFP.

His deputy, Bassey Inyang, later said that in addition to the three men, who were senior managers of the company, two women and two children were also seized. He said that all seven are Indian nationals. There was no immediate confirmation from Indian diplomatic sources or from the company.

Two policemen who were guarding the compound were killed in the attack, the officers said. No one has officially claimed responsibility for the kidnapping, the second to hit the company in less than two weeks. A community member living near the petrochemicals plant said that locals were angry with Indorama for bringing in Indian staff and paying them more than Nigerian workers for similar jobs.

On May 19, two Indian nationals were abducted from the company's premises on the outskirts of Port Harcourt, the capital of oil-rich Rivers State. One civilian was killed in that incident and another injured.

The company is still referred to in the region as Eleme Petrochemical Company. Eleme was a state-run firm before it was sold to Indorama, an Indonesian group, last year.

Around 40 foreigners were taken hostage in the Niger Delta last month. Some 180 foreigners -- mostly oil workers -- have been seized by militant groups and armed gangs in the region in the past 18 months. Most were released after a few days or a few weeks.

Four US oil workers were released by their unidentified captors on Wednesday and the most high-profile armed group in the region, the Movement for the Emancipation of the Niger Delta (MEND), had planned to release the six oil workers it is holding this week. But MEND said today the release was delayed because of logistical problems in handing the men over to their employer. "They would have been released today but we requested for a chopper and this request was turned down," a spokesman or the group said in an email to AFP.