A blast on the outskirts of Nigeria's capital Abuja killed 19 people on Thursday, according to police.
An apparant car bomb exploded in the suburb of Nyanya near the site of an April 14 bomb attack that killed at least 75 people during the morning rush hour at a bus station.
Police Superintendent Frank Mba told reporters Friday the toll is up to 19 dead with as many wounded being treated in the hospitals. Six cars were burned up in the blast, he said.
Witnesses said a car laden with explosives drove close to the checkpoint and a man jumped out and ran as it blew up.
"There was a loud blast then a ball of fire," Lateef Adebayo, a witness, told Reuters by telephone. "There were many dead bodies and ambulances were rushing there."
Another witness, Joe Udofia, said there was a "deafening explosion, then the area near Nyanya Bridge was on fire. There were many people in the vicinity."
No group claimed credit for the blast. The religiously conservative armed group Boko Haram claimed responsibility for the April 14 bombing and threatened further attacks. The group is waging an insurgency against the government to carve out an Islamic administration in Africa's largest oil producing country.
The blast came a week before Abuja is due to host the World Economic Forum on Africa, an annual gathering which brings together international leaders, policy makers and entrepreneurs.
Nigeria's government has announced a major security operation to protect the capital during the May 7-9 forum. The government is deploying 6,000 police to protect the gathering which Chinese Premier Li Keqiang is expected to attend.