WARRI, Nigeria (Reuters) -- Villagers fled Nigeria's lawless delta on Wednesday amid fears of military reprisals after a wave of attacks on foreign oil companies by ethnic Ijaw militia.
The army deployed more troops to key installations and oil companies tightened security around their offices a day after heavily armed men stormed the headquarters of Italian oil firm Agip, robbing a bank on the premises and killing eight policemen and one civilian.
"There are soldiers everywhere, and I don't want my three girls in the firing line," said Return Powei, from the remote village of Ogbotobo. "Our youths run into the forest when they hear the soldiers are coming. Everyone is moving out of Ogbotobo."
It was not clear if the attack on Agip, a unit of Italy's ENI, was the work of the Movement for the Emancipation of the Niger Delta, whose five-week campaign of sabotage and kidnapping has helped push world oil prices to four-month highs. (Details on Agip attack)
The movement pledged on Wednesday to make Royal Dutch Shell suffer, unless it pays $1.5 billion to delta villages in compensation for decades of oil pollution.
The government has set up a committee to negotiate the release of four foreign oil workers -- an American, Briton, Bulgarian and Honduran -- kidnapped from a Shell oilfield on January 11.
"In principle, we have assurances the hostages will be released ... We believe it will be this week," said a spokesman for state of Bayelsa, one of six delta states. "There will be no military reprisals."
However, diplomats say the government has given similar messages every day since the abduction and the militants have consistently denied being in any talks.
"The hostages are in good health ... and are going nowhere for as long as our demands are not met," said the group, which also demands the release of two imprisoned Ijaw leaders and more local control over the delta's huge oil wealth.
At the riverside in the delta city of Warri, villagers from outlying villages arrived in boats packed with household possessions, fearing military reprisals for the killing of a dozen soldiers on a Shell oil platform last week.
Shell has already withdrawn 500 staff and cut its output by 221,000 barrels a day, or one tenth of Nigerian exports.
Hundreds of contractors have also fled as the military deploys extra troops to platforms and shipping terminals across the vast region of mangrove swamps and tidal creeks.
Oil unions have threatened to pull out from the delta, which produces almost all Nigeria's 2.4 million barrels a day, if security deteriorates further.
"There is palpable fear in the air that another Odi is in the making," said ThisDay newspaper on Wednesday. Rights groups say the 1999 raid by troops killed hundreds in the delta village of Odi to avenge the killing of 12 policemen.
The militants vowed to respond in kind to any military reprisals and again warned foreigners to leave the delta. Nigeria's secret service released three men detained this week for alleged links to the kidnappers. The militants had distanced themselves from them, saying they were profiteers.
"These people were arrested for being unable to provide the hostages after they were paid," the militants said. "The hostages were not being held for money."
The captives will be freed only in return for the release of militia chief Mujahid Dukubo-Asari and former Bayelsa state governor Diepreye Alamieyeseigha, who was impeached for money laundering last month, the group said.