Security to the fore as Nigeria hosts 'Africa's Davos'

 Nigeria hosts the World Economic Forum on Africa summit this week under tight security after two deadly car bomb attacks raised fears about a possible spread of militant violence.

Thousands of police and army personnel will be on the streets of the capital, Abuja, as delegates arrive for the Wednesday to Friday summit known as "Africa's Davos".

President Goodluck Jonathan heads the list of more than 1,000 participants and Chinese Premier Li Keqiang is also set to attend, as part of his first tour of Africa since taking office last year.

Restrictions are already in place at airports in Abuja and the financial capital, Lagos, after a warning that two top city hotels were under threat.

Schools and government offices in the capital will also be closed.

Car bombs, abductions

Security issues have dominated the run-up to the conference, which the government hopes will demonstrate its potential to overseas investors as a place to do business.

Two separate car bomb attacks over three weeks in the same Abuja suburb killed more than 90 and left scores more injured.

The first on April 14 was claimed by Boko Haram, which has been waging an increasingly deadly insurgency in the country's north since 2009.

The group is suspected for the copy-cat blast last Thursday.

The extremists, who want to create a hardline Islamic state in northern Nigeria, are also suspected of abducting nearly 300 schoolgirls from the town of Chibok in Borno state, which has borne the brunt of the violence.

Their disappearance three weeks ago has triggered protests across Nigeria, while a social media campaign -- #bringbackourgirls -- has piled pressure on Jonathan's government and won growing international support.

Finance minister Ngozi Okonjo-Iweala, a Davos summit regular, and Nwanze Okidegbe, the chief economic adviser to President Goodluck Jonathan, have assured delegates that their safety will be paramount.

"Our security planning... will be the largest security operation ever mounted in this country for an international summit," they said in a statement after the April 14 attack.

"In total, over 6 000 security personnel, consisting of police and army, will be deployed, covering a secure area the size of 250 square kilometres (96.5 square miles).