Car rams supporters of Liberia's President-elect Boakai, injuring at least 16

Police said they were searching hospitals for other victims, while Boakai's Unity Party said at least 10 people had died in the incident.

"I can't confirm the total number (of casualties), but at JFK I know there are 16 persons, 12 males and four females," police official Melvin Sacko told AFP, referring to a local hospital.

Boakai's party said at least 10 people were killed when a car drove into a group of supporters celebrating outside their headquarters around 9 pm (2100 GMT).

"It just picked up with speed and ran into the supporters, and as we speak about 10 people are dead," party spokesman Mohammed Ali told AFP.

Videos posted on social media showed bloodied people lying on the ground, some receiving medical assistance.

Boakai was officially declared the winner of last week's election on Monday with 50.64 percent of the vote, against 49.36 percent of the vote for incumbent George Weah.

The outgoing president and former football star won praise abroad for conceding and promoting a non-violent transition in a region marred by coups.