At least 40 foreign oil workers have been kidnapped since January in Nigeria
Nigeria's main oil workers union PENGASSAN threatened to pull out of the volatile Niger Delta region following a wave of kidnappings and violence.
"We are considering pulling out of the region as we have lost confidence in the security agencies," President of the Petroleum and Natural Gas Senior Staff Association (PENGASSAN) Peter Esele told Agence France-Presse.
He said despite a clampdown on separatist militants terrorising oil firms and facilities in the region, the Delta was increasingly becoming unsafe for oil workers.
Esele said a PENGASSAN member who worked for the Anglo-Dutch oil giant Shell and kidnapped on August 8 had yet to be found, and urged the government of the southern state of Bayelsa to work for his release.
At least 40 foreign oil workers have been kidnapped since January, with around 15 abducted in the past two weeks.
Ten of them have since been released but five -- an American, a Briton, a German, an Irishman and a Lebanese construction worker -- are still in captivity.