Explosion at Nigerian govt HQ

An explosion occurred outside a government building in Nigeria's southern oil hub of Port Harcourt today, according to a reporter on the scene.

A bomb appeared to have exploded against the building that houses the state governor's office and other major government offices for southern Rivers state.

Pieces of a car could be seen around the explosion site and an AP reporter who arrived shortly after the incident could see smoke still rising.

The explosion came less than an hour after a militant group, the Movement for the Emancipation of the Niger Delta, said it had placed two car bombs in Nigeria's oil-rich delta, threatening in an email to detonate them "shortly".

Firefighters and police arrived on the scene soon after the explosion. It was not immediately clear if anyone was injured.

Separately, military officials announced an overnight bombing of a water pipeline leading into an oil refinery in the southern oil-producing region.

Brigadier General Alfred Ilogho said dynamite had been placed under a water pipe leading to a refinery in Warri, a town in Nigeria's southern Delta state, but that the bombing had not affected production at the government-owned refinery.

Residents in the area reported hearing a large explosion around midnight local time (11pm Irish time).

The incidents cap off a week of violent strikes against petroleum companies in Africa's largest oil producer. On Monday, militants detonated two car bombs at oil company compounds in the oil-producing hub of Port Harcourt.

On Thursday, armed men raided a Total SA pumping station in an attack that left three police guards dead, while another group took over an Eni SpA facility. The companies shut down production at both facilities, suspending about 80,000 barrels per day in all.

Nigeria has seen its typical oil production of 2.5 million barrels per day cut by a quarter this year by a series of attacks and hostage-takings by militants, some seeking ransoms and others political influence.

Gangs and politically-minded militants say attacking the oil infrastructure is the only way for them to get a share of the country's oil wealth.

In a sign that the security situation could be worsening, Royal Dutch Shell PLC began evacuating all dependents of foreign employees from the delta region this week, citing the deteriorating security situation following the car bombs, one of which was set off in a Shell complex.