Dozens of people are reported to have been killed in the latest outbreak of communal violence in Nigeria's troubled Niger Delta region.

It appears to have been a particularly brutal clash, even by the standards of the area.

Local villagers said that about 40 people died in the fighting between two communities of the Isoko ethnic group in the eastern part of Delta state.

Police in the area said that four of their men had been killed and that weapons had been stolen when a police station was overrun.

A reporter who travelled to the area on Wednesday night saw the bodies of five civilians and two policemen, but local people said that many more bodies had already been buried since the violence erupted on Tuesday night.

Oil pipes

The dispute between the two villages was apparently over the equitable sharing of some discarded oil pipes which local people said had been given to them by the oil company, Shell.

The company denies having been involved in the distribution.

Discarded pipelines are used for construction and sections are also used for water storage.

That such an apparently trivial issue could have caused such mayhem points to the desperate levels of lawlessness now prevalent in the Niger Delta, where impoverished local communities live in close proximity to Nigeria's lucrative oil industry.

Nigeria's Government has already expressed outrage at the growing wave of violence in the Niger Delta and has threatened to introduce a state of emergency if local governors cannot improve security.