ABUJA, Nigeria – A car loaded with explosives crashed into the main United Nations building in Nigeria’s capital and exploded Friday, killing at least 18 people in one of the deadliest assaults on the international body in a decade.

A radical Muslim sect blamed for a series of attacks in the country claimed responsibility for the bombing, a major escalation of its sectarian fight against Nigeria’s weak central government.

The brazen assault in a neighborhood surrounded by heavily fortified diplomatic posts represented the first suicide attack to target foreigners in oil-rich Nigeria, where people already live in fear of the radical Boko Haram sect.

The group, which has reported links to al-Qaida, wants to implement a strict version of Shariah law in the nation and is vehemently opposed to Western education and culture.

While police officers and local officials have primarily borne the brunt of Boko Haram’s rage, now everyone seems to be a target in a nation often divided by religion and ethnicity.

“It is an attack on the global community,” said Viola Onwuliri, a junior Nigerian foreign minister, as she looked at the bomb site.

A sedan loaded with explosives crashed through two gates at the exit of the United Nations compound Friday morning as guards tried in vain to stop it, witnesses said.

The suicide bomber inside drove the car through the glass front of the main reception area of the building and detonated the explosives, inflicting the most damage possible, a spokesman for the Nigerian National Emergency Management Agency said.