Nigeria, rich in oil and Africa's most populous country, is seen as an emerging economic giant.
But after Monday's massive bombing at a bus station a few kilometres from the seat of government in Abuja by the Islamist group Boko Haram, that might be debatable.
The attack, which left 71 dead, followed an assault on the Giwa security barracks in the middle of March by the same group, which claimed to have freed nearly 2,000 detainees.
Two weeks later, heavy gunfire from members of the group was reported near the presidential palace and the headquarters of the State Security Service.
"We are seeing an increase in attacks by Boko Haram," said Mr John Campbell, former US ambassador to Nigeria and a senior fellow at the Council on Foreign Relations in New York.
"The fact that they have targeted military installations and the presidential villa shows Abuja is no longer safe," he told The Straits Times on Wednesday.
Coined by northern Muslims, the name Boko Haram translates loosely as "Western education is forbidden". The group came into the spotlight in 2009.
"Boko Haram is dangerous," Dr C. Nna-Emeka Okereke, a security expert based in Abuja, told The Straits Times.
"It is now targeting critical infrastructure. It is spreading from the north-east to other parts of the country."
He and other security watchers say the bombing shattered assurances by the government that it has managed to contain the grassroots militant group, classified as a terrorist organisation by the United States last year, to the country's north-east.
With the modus operandi of the group similar to that of the global Al-Qaeda, the attack also turns the spotlight on major terrorist groups operating in Africa as the continent tries to attract investors.
These include the Somali militant group Al-Shabaab and the Al-Qaeda in the Arabian Peninsula in north Africa. There is also Al-Qaeda in Islamic Maghreb, which has its origins in Yemen but now has wide connections in north and west Africa.
"Africa is emerging into an epicentre of terrorism," said Singapore-based terrorism expert Rohan Gunaratna, who was recently in Nigeria.
"In the '80s and '90s, the threat was in north Africa, but with counter-terrorism operations and pressure on terrorist groups, the threat has shifted farther south," he said.
"Nigeria is facing a significant challenge today because Boko Haram has received training from the other major Al-Qaeda-linked groups."
The Abuja bombing, together with threats elsewhere in Africa, will affect investors, said Mr Alex Vines, research director and Africa programme head at Chatham House, London. Prior to the blast, "Nigeria has been listed among economies to watch after India and China", he said.
A BBC report on economic projections by the World Bank and Goldman Sachs suggests that Nigeria's economy could grow from US$260 billion (S$325 billion) in 2012 to US$4.91 trillion (S$6.13 trillion) by 2050.
Among investors in the country is Singapore's Temasek Holdings, which has invested US$150 million in Nigerian firm Seven Energy as part of its expansion into emerging markets.
This article was published on April 18 in The Straits Times.
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