LAGOS — Security forces on Sunday combed the Niger Delta for 12 foreign seafarers seized two days earlier from a cargo ship, while three sailors taken hostage in May were reportedly freed.
No-one has yet claimed responsiblity for the capture of the BBC Polonia, registered in the Caribbean nation of Antigua and Barbuda, and its multinational crew, including its 71-year-old German captain.
"Police in Bonny and adjoining riverine areas (are) closely monitoring for possible rescue/arrest," said Rita Abbey, a police spokeswoman in Rivers State, adding that an air and sea operation was underway "to locate hideouts".
"There has not been any contact from the group that carried out the attack," Lieutenant Colonel Timothy Antigha, spokesman for a special security force deployed in the area, told AFP.
"But the various arms of the military are alert and searching the area".
Hundreds of locals and foreigners have been abducted in the Niger Delta in recent years, against the backdrop of conflict in the oil-producing region where a government amnesty has failed to totally snuff out militancy.
Most hostages end up being freed after a few days or weeks, very often after a ransom is paid.
Two Russian sailors and a Lithuanian skipper captured in May in an attack on a Greek-owned ship off Cameroon have meanwhile been freed in Nigeria, a Russian sailors' union and a Lithuanian shipping firm said.
Lithuania's foreign ministry confirmed that its citizen had been released and would soon return home.
Germany has confirmed that two of its citizens were among the 12 seafarers captured in Friday's incident, during which a Ukrainian seaman was reportedly injured.
Its foreign ministry has set up a crisis team and "is working in cooperation with the Nigerian authorities to ensure that the two Germans are freed," a spokeswoman told AFP in Berlin.
Others on board included a number of Russians, a Latvian and a Lithuanian, who was identified by the Lithuanian government as Alexei Sysoi.
German officials refuted a suggested by the Nigerian navy on Saturday that the ship was German-flagged, saying that it was not registered in that country.
MarineTraffic.com, a website that tracks ships' movements, reported that the BBC Polonia was en route to the Nigerian port of Onne, which is situated on the Bonny estuary in the Niger Delta.
Abbey said security forces suspect Friday's attack was the work of a group led by Farah Dagogo, a former commander of the Movement for the Emancipation of the Niger Delta (MEND) who surrendered under a 2009 government amnesty.
But Antigha, of the special security force, said he had no idea who was behind the incident. He added: "We are sure that in a short time, we should be able to be clear about who is holding them".
