Nigerian authorities say gunmen have kidnapped another foreign oil worker in southern Nigeria - the 15th worker taken hostage in the past 12 days.

A Rivers State police spokeswoman says a Lebanese man was abducted Wednesday from his car by unidentified attackers in the Niger Delta region.

Late Tuesday, Nigerian President Olusegun Obasanjo said his government will no longer tolerate kidnappings in the oil-rich Delta.

In a statement, the president said security forces will begin round-the-clock patrols of the Niger Delta region. He also threatened to sanction companies if they pay ransom to kidnappers.

Kidnappings have become common in the Delta, where militants are demanding that local communities receive a larger share of oil revenues.

Nine of the 15 oil workers taken hostage this month have been released unharmed. The whereabouts of the other six, including the Lebanese man, remain unknown.

In all cases, it is unclear who seized the workers or whether ransom money was demanded for their release.

At the start of the year, Nigeria was producing 2.5 million barrels of oil per day. But kidnappings and attacks on oil facilities have cut the country's oil production by at least 20 percent since February.

Some information for this report was provided by AFP and AP.