FREETOWN- Sierra Leone chooses a new president on Saturday following a delay caused by a ruling party-backed court case over alleged electoral fraud, spiking tensions following an already fractious campaign.

The West African nation's 3.1 million voters will choose between the ruling All Peoples' Congress (APC) candidate Samura Kamara and opposition challenger Julius Maada Bio of the Sierra Leone People's Party (SLPP).

Bio, a former junta leader, won by just 15,000 votes in the March 7 first round,but failed to attain the 55 percent of ballots needed to win outright, triggering a runoff. Turnout was over 80 percent. The SLPP candidate has accused the APC of using police intimidation against his party and the electoral commission, and of sponsoring a court case alleging electoral fraud in order to cling to power.

Police have reported a string of attacks on candidates and supporters on both sides since the first round, making voters nervous ahead of polling day.

Bio was clear that "nothing" more would get in the way of the vote after a four-day delay caused by court proceedings.

Sierra Leone, which emerged from a brutal civil war in 2002, has remained largely peaceful since then.

The country's High Court on Monday lifted an injunction imposed on Saturday that halted the runoff, as the APC alleged some ballots were tampered with.

International and domestic observers hailed the March 7 vote as fair and credible despite some organisational hitches.

Kamara has declared himself "satisfied" with the court decision, and reiterated calls for a peaceful vote.

The decade-long rule of outgoing president Ernest Bai Koroma was marked by the 2014-16 Ebola crisis, which killed almost 4,000 people, and the deadly mudslide that hit Freetown in 2017, killing at least 400 more.

The APC broadly relies on the Temne and Limba people in its northern strongholds,while the SLPP is more popular in the south with the Mende ethnic group.

Some candidates and supporters have used ethnic slurs at campaign rallies, and the police and international observers have raised concerns over such rhetoric in recent weeks.