An explosion in the oil-rich Niger Delta in southern Nigeria blew up oil pipelines on Wednesday, leading to massive oil spilling, but it was said to be unlinked with militants holding nine foreign oil workers.

Jomo Gbomo, a self-described spokesman for the militants, in an email statement to Xinhua, denied knowledge of any of the attacks by their members.

"No. If this actually happened, it may have been carried out by local villagers or thieves," Gbomo said.

"We however do not believe any such attacks took place and believe it to be part of a propaganda campaign by the Nigerian military to support a future attack on communities in that vicinity," he said.

A local journalist in the oil city of Warri quoted residents of Gbaramatu community as saying that the explosion was from an un- detonated bomb used in February by the military in the community while destroying barges belonging to oil thieves.

Nigerian newspapers reported that the militants on Tuesday continued their onslaught on oil facilities in the Niger Delta by attacking the Chanomi creek manifold and a tanker ship in Delta state.

Royal Dutch Shell's local subsidiary, SPDC, a major oil company operating in the area, made no confirmation on whether the affected pipelines belonged to it.

Shell and Gbaramatu communities have been having a face-off since January, leading to the abduction of nine foreign oil workers of Houston, Texas-based oil service company, Willbros Group.

The oil service company was laying pipelines for Shell when its workers were abducted. The nine hostages, including three Americans, two Egyptians, two Thais, one Briton and one Filipino, were seized on February 18 by the militants belonging to the self- styled Movement for the Emancipation of the Niger Delta (MEND).

A government committee headed by James Ibori, governor of the southern state of Delta, was set up immediately after the seizure to secure the speedy release of the hostages through dialogue.

Gbomo said they "have had no contact with the Ibori led committee and have no intention of doing so."

"Recently we intimated the media of our willingness to release all low value hostages. The Delta state government today (Monday) capitalized on this suggestion, claiming we had undertaken to release the hostages in batches. This is a fraudulent claim," he said.

"In this regard, the suggested release of any hostage has been suspended indefinitely," he said.

Recent attacks by the militants on oil facilities in the west African country, the largest oil producer in Africa, has cut production by 455,000 barrels per day , or 19 percent of the country's total output, and help push up world oil prices.

Source: Xinhua