JOHANNESBURG, South Africa -- Nigerian President Goodluck Jonathan blamed Boko Haram for an explosion that killed scores of people Monday at a bus station outside the capital, Abuja, calling the Islamic militant group an "unnecessary distraction" and a temporary problem.
Jonathan, whose leadership has been under intense pressure over his failure to curb the rebellion of Boko Haram in the north of the country, called on Nigerians to be more vigilant about terror attacks.
Police confirmed that at least 71 people were killed and 124 injured in the early morning blast. But some local media suggested the death toll could be almost 90.
No group immediately claimed responsibility for the explosion; however, it bore the hallmarks of previous attacks by Boko Haram, which has twice launched suicide bombings in the capital.
One targeted the United Nations headquarters and killed at least 21 people in 2011. The other was aimed at the police headquarters and killed up to six people that same year. The latter attack was believed to have been the first time that Boko Haram used a suicide bomber.
The majority of Boko Haram's attacks have been carried out in northern Nigeria. The group opposes a Western lifestyle and secular education and aims to impose Islamic law across the country, which is divided between a mostly Muslim north and predominantly Christian south.
Nigerians tweeted photographs of people who were killed in Monday's blast under the hashtag #NotJustNumbers. There were also appeals for blood donations.
Officials offered different accounts of what happened. Nigeria's National Emergency Management Agency reported that the bomb was concealed in a vehicle, while an official from the National Security and Defense Corps said it was believed that the bomb was buried at the bus station, the Associated Press reported.
The Nigerian Vanguard newspaper reported that four people drove a car into the Nyanya bus station and fled, leaving the vehicle which exploded soon after.
A bus driver, Dalhatu Garba, told local media that the bomb was concealed in a VW Golf car. A large crater was left in front of a bus, according to the reports.
"We just heard a loud explosion, and many people died instantly. In fact, many people were scattered into pieces," Garba said.
Limbs were strewn over the ground, while people trapped in burning vehicles screamed for help, according to witnesses. Others described survivors wailing in anguish as they fled the scene.
Visiting the site of the explosion amid heavy security, Jonathan said, "The issue of Boko Haram is temporary. Surely, we will get over it."
The group has launched dozens of attacks in the northeast of the country this year. At least 1,500 people have been killed in the incidents and in reprisals by the country's security forces, according to the international rights group Amnesty International.
The explosion in Abuja followed reports that Boko Haram had launched multiple attacks on villages in northern Nigeria, killing 135 people since Wednesday.
Last month, Amnesty International reported that 600 people were killed after the group attacked a barracks in Maiduguri, the capital of Borno state, to free prisoners. Most of the victims were escaping detainees, shot by security forces, the report said.
International rights groups, including Human Rights Watch, say abuses by security forces have made it easier for Boko Haram to gain sympathy and recruit followers. They have called on Boko Haram to halt its attacks, many of which target civilians.