PORT HARCOURT, Nigeria (AFX) - An explosion rocked the outside of a government building in Nigeria's southern oil hub Saturday, soon after the military reported an overnight bombing of a water pipeline leading into a refinery.
The attacks came at the end of a week of violent strikes against petroleum companies in Africa's largest oil-producing nation. Militant groups say people in the oil region aren't benefiting enough from the wealth.
There was no immediate confirmation that the explosion at the government building in Port Harcourt was a bomb, but the incident occurred less than hour after a militant group said it had put two car bombs in the oil-rich Niger River delta and threatened to detonate them 'shortly.'
Pieces of a car were scattered around the explosion site when an Associated Press reporter arrived shortly after the blast. There were no immediate reports of injuries.
Earlier, Brig. Gen. Alfred Ilogho said dynamite had been set off under a water pipe leading to a refinery in the town of Warri, but the blast did not affect production at the government-owned refinery.
Residents in the area reported hearing a large explosion around midnight.
It was a violent week in the oil region.
On Monday, militants blew up two car bombs at oil company compounds in Port Harcourt.
Three days later, armed men raided a Total SA pumping station in an attack that killed three police guards, while another group took over an Eni SpA facility. The companies shut down production at both facilities, about 80,000 barrels per day in all.
Nigeria has seen its typical daily oil production of 2.5 million barrels drop by a quarter this year because of attacks and hostage-takings by militant groups and criminal gangs -- some seeking ransoms and others demanding more political power and income for the region's people.
Royal Dutch Shell PLC began evacuating all dependents of its foreign employees from the delta region this week, citing the worsening security situation after Monday's car bombs -- one of which was set off in a Shell complex.
Associated Press writer Katharine Houreld in Lagos, Nigeria, contributed to this report.
Copyright 2006 Associated Press. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.