Police did not give a reason for the incident, which occurred yesterday evening, but a spokesman for Boakai’s Unity Party said they believed it was a deliberate act.

The driver had fled the scene, police said.

“Two people are dead and one is in critical condition,” said Sia Wata Camanor, a senior member of staff at the John F Kennedy (JFK) hospital in the capital, Monrovia.

Twenty others had been injured, she told AFP.

Police were searching hospitals for other victims.

Boakai’s party said the car drove into supporters celebrating outside their headquarters between 9pm and 10pm yesterday, after Boakai was officially declared the winner of last week’s election.

“It just picked up with speed and ran into the supporters,” party spokesman Mohammed Ali told AFP on Monday evening.

Ali quoted witnesses as saying the driver of the car, which was parked near the celebrating supporters, flashed the headlights, then turned them off and drove into the crowd.

He said it was hard to believe the vehicle had experienced a mechanical failure or that the brakes had failed.

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

Police official Melvin Sacko said yesterday that 16 casualties – 12 men and four women – had been taken to the JFK hospital.

Liberia’s electoral commission said yesterday that Boakai had won 50.64% of the vote, against 49.36% for outgoing president George Weah.