Gunmen shot dead two policemen and abducted two Lebanese nationals on Wednesday from a construction site in Nigeria's southern delta region, witnesses and police said.
The gunmen approached in two speed boats, killed two policemen guarding the site in a gun fight, snatched the two foreign workers and fled in the craft, Anisim Butswat, spokesman for Bayelsa state police said.
The attack was in the Ogbia local area in Bayelsa state, the same area where three expatriate construction workers were kidnapped in November.
"We have launched a massive man hunt for the kidnappers and their victims," Butswat said. "We want to assure Bayelsans to go about their legitimate duties as the police are on top of the situation."
Nigeria, Africa's largest economy and leading energy producer, is one of the world's most dangerous countries for kidnapping, mostly in the prosperous south where gangs net millions of dollars from ransoms.