Police in Nigeria say two construction workers kidnapped earlier this week have been freed.
The sources provided few details on the release of the men, who are Indian and Lebanese citizens. The men were kidnapped from their work site in the oil-producing Niger Delta region on Friday.
A military official, Brigadier General Alfred Ilogho, told the Reuters News Agency that the kidnappers had no way to move their hostages because all the waterways were blocked and so they released them.
There is still no news about a Dutch employee of a German construction company who was kidnapped separately on the same day from the city of Port Harcourt.
No group has claimed responsibility for either of the kidnappings.
Armed groups have kidnapped more than 60 foreigners in the Delta this year alone.
The kidnappings and attacks have reduced Nigeria's oil production by about 20 percent since February 2006.
Some of the abductions have been carried out by militants demanding that local villages get more of the region's oil wealth. Others are believed to be the work of criminal gangs seeking ransom.
Most of the hostages have been released unharmed.
Some information for this report was provided by AFP and Reuters.