A Nigerian official says at least five people were killed when militants set fire to an oil tanker loading dock in Lagos -- in the first known attack by Niger Delta rebels in the country's commercial capital.
Emergency services spokesman Geoffrey Boukoru told reporters Monday that the fire also damaged pipelines at the facility.
The Movement for the Emancipation of the Niger Delta, or MEND, says its fighters carried out the attack at the Atlas Cove Jetty late on Sunday.
Witnesses say the militants exchanged fire with naval officers before setting off an explosion.
The group has claimed responsibility for scores of attacks and kidnappings in its home Niger Delta region, the center of Nigeria's oil industry.
MEND has increased its assaults since the Nigerian military launched an offensive against the group in May.
Nigeria's oil production has dropped by at least 25 percent since late 2005, when militants began a wave of attacks against oil facilities in the Niger Delta.
MEND says it is fighting so Niger Delta residents can get more of their region's oil wealth. The government describes the militants as criminals.
However, Nigerian President Umaru Yar'Adua recently offered amnesty to militants who surrender their weapons and renounce violence.
Lawyers for a key MEND leader, Henry Okah, say he has accepted the amnesty offer. The charges against Okah may be dropped at a Monday hearing.
Okah has been in detention since September 2007.
Some information for this report was provided by AFP and Reuters.