ABUJA: Nigeria’s capital was on alert yesterday after an explosion outside a popular shopping centre, in the latest attack likely to be blamed on Boko Haram Islamists.

The first explosion happened at about 9pm at a shopping plaza in the city’s Wuse II district, said Yushau Shuaib, spokesman for the National Emergency Management Agency (Nema).

Rescue workers then rushed to the scene and cordoned off the area, where a unexploded bomb was later discovered, an official said.

“When we were trying to find out what is happening, the anti-bomb squad discovered another one. They just detonated it,” said the head of Nema’s Abuja office, Ishaya Chonoko.

“The good thing is that there was no report of human casualty,” he added.

The area was swarming with rescue workers overnight, as security forces kept journalists hundreds of metres away.

When the cordon had been cleared, an AFP reporter saw that the windows of shops adjacent to the Banex Plaza shopping mall had been shattered, but the main centre had evidently not been affected.

The plaza, in a prominent commercial area of Nigeria’s capital, is popular with Nigerians and foreigners.

A police statement called the blast “a low-level explosion” and said “intensive” surveillance patrols were ongoing around the city that has been repeatedly attacked by Boko Haram.

A suicide bomb attack on UN headquarters in Abuja in August killed at least 25 people, while another at the Abuja office of one of the country’s most prominent newspapers left four dead.

Most recently, on June 22, a blast went off outside a nightclub in Abuja that shattered the windows of nearby buildings, but caused no casualties.

No group has yet claimed responsibility for the latest attack.

The US embassy in Nigeria issued an “emergency message to inform US citizens of potential threats against US installations during the July 4 holiday week”.

The statement posted on the embassy website said the US government was working with Nigeria’s security to boost security measures through the independence holiday.

In Abuja, Americans remain barred from visiting places of worship as well as nearby commercial establishments and must return to their homes by midnight, the statement said.

Boko Haram has repeatedly attacked churches, typically on Sundays and holidays.

Last month, Washington designated three Boko Haram leaders as global terrorists, and the group has previously threatened to strike American interests.

Much of Boko Haram’s violence has been concentrated in northern Nigeria. – Sapa-AFP