* Shooting follows raids on militant camps

* Oil firms fear retaliatory attacks

* Production largely unaffected

(Adds military comment, background)

By Segun Owen

WARRI, Nigeria, May 20 (Reuters) - Shooting broke out in the Nigerian oil port city of Warri on Wednesday following days of military helicopter and gunboat raids on militant camps in the surrounding creeks, witnesses said.

One local journalist at the scene said there appeared to be a gun battle between navy personnel and local youths near a naval base in the Miller Waterside area of Warri. Other residents said they could hear gunshots in the port area.

"It was just a normal cleansing of areas which were thought to be harbouring criminals," military spokesman Colonel Rabe Abubakar said. "If there was shooting it was to warn the criminals from coming nearer."

Nigeria last week launched its biggest military offensive for years in the Niger Delta, bombarding militant camps near Warri from the air and sea before sending in hundreds of ground troops to try to flush rebel fighters out of local communities.

Some foreign oil firms have evacuated non-essential personnel from the western Niger Delta around Warri for fear that militant fighters will launch retaliatory attacks on Africa's biggest oil and gas industry, security sources say.

Italian oil and gas company Eni SpA <ENI.MI> on Wednesday declared force majeure on exports from its Brass River terminal in neighbouring Bayelsa state after militant threats to blockade key waterways to try to prevent oil exports.

An industry source said the total oil output covered by the measure was 52,000 barrels per day (bpd). [ID:nLK405215]

Royal Dutch Shell <RDSa.L> said it was also investigating reports of an attack on one of its Niger Delta facilities.

NO PRODUCTION IMPACT SO FAR

State oil company NNPC said oil production was so far largely unaffected. Crude oil output was running at around 1.6 million barrels per day before the latest unrest. [ID:nLJ162350]

"The success of the military campaign means that production can go on ... right now there is no significant impact on production," NNPC spokesman Levi Ajuonoma said.

He said Eni's force majeure was "a precautionary measure so these contractual obligations are put on alert".

The heavy military presence has made independent access to remote communities in the creeks around Warri virtually impossible since clashes broke out last Wednesday, making it difficult to assess the numbers of displaced or wounded.

Local rights groups say the military's use of helicopter gunships has triggered a "mass evacuation" of villagers and have urged restraint by the security forces. They have asked both sides to allow humanitarian access to those displaced.

The areas hit by the military, including Miller Waterside, have been largely Ijaw communities, the largest ethnic group in the Niger Delta, prompting accusations of a targeted campaign.

"It has become ethnic cleansing against the Ijaw nation," said Owen Nanakumor, an Ijaw community leader in Warri.

He said three people had been killed in Wednesday's fighting -- including a woman and a 45-year old man at Ogbe Ijor market near Miller Waterside -- and around 30 people arrested.

The military denies innocent civilians have been killed and has repeatedly said it is trying to flush out criminals hiding in communities.

"We are applying minimum force .... There are no casualties on the civilian side. Whoever is injured must have taken part in the fighting. It means they are criminals and if we get them, we will arrest them," Abubakar said. (For full Reuters Africa coverage and to have your say on the top issues, visit: http://af.reuters.com/ ) (Writing and additional reporting by Nick Tattersall; Editing by Jon Hemming)

AlertNet news is provided by