Two oil worker hostages, a Moroccan and a Belgian, were released on Monday after a week in captivity, a witness said on Monday.
The two were kidnapped by armed men in Nigeria’s southern delta on Thursday, part of a string of such abductions.
The wave of kidnappings coincides with an upsurge in militant attacks against the oil industry which has cut oil production by 25 percent in the world’s eighth largest exporter since February.