Dozens of people have been injured in clashes between supporters of rival presidential candidates in Sierra Leone's capital, Freetown.
Ernest Koroma (L) faces Solomon Berewa in the final round
Police fired tear gas to break up the clashes, the latest in a series in the run up to the second round of voting.
President Ahmad Tejan Kabbah had earlier threatened to impose a state of emergency if violence continued.
The ruling party's Solomon Berewa takes on opposition candidate Ernest Koroma in next Saturday's run-off.
Foreign observers, who praised the first round, appealed for calm before the final round.
Sierra Leone is still recovering from a nine-year civil war that ended in 2002 and cost the lives of more than 50,000 people.
Saturday's clashes took place close to the headquarters of the governing Sierra Leone People's Party.
Some of those involved had machetes, clubs and knives.
Police used tear gas and set up roadblocks to separate the two sides.
Over the past week there have been several clashes between supporters of Mr Berewa and Mr Koroma, of the opposition APC Party.
Mr Koroma had to abandon a campaign in the east of the country after one clash.
Following a meeting on Saturday the two candidates are reported to have agreed to hold a peace rally on Monday in an effort to defuse the situation.
In a TV address, Mr Kabbah had said the country had suffered too much to allow chaos and civil unrest again.
He urged the two rival candidates to call for calm.
BBC West Africa correspondent Will Ross says that although most Sierra Leoneans are desperate for peace, the fear is that a cycle of retaliation could see the violence escalate.
In the first round on 11 August, Mr Koroma took 44% of the vote to Mr Berewa's 38%.