Sporadic gunfire can be heard in Ivory Coast's main city, Abidjan, a day after former President Laurent Gbagbo was arrested.
The BBC's Mark Doyle in the city says it is not clear whether pro-Gbagbo forces or criminals are responsible.
But he says mortars are also being fired.
Mr Gbagbo was seized after refusing to accept defeat in last year's elections. His successor, Alassane Ouattara, has appealed for the violence to end.
Our correspondent says Mr Ouattara's first priority will be to restore security.
A joint operation by pro-Ouattara forces, the UN and French military captured Mr Gbagbo from his official residence, where he had been under siege for more than a week.
Mr Ouattara said Mr Gbagbo would be put on trial, and said a truth and reconciliation commission would be set up.
Some 1,500 people have been killed across the country and a million forced from their homes during the four-month stand-off in the world's largest cocoa producer.
The UN and French forces intervened after they accused Mr Gbagbo's forces of using heavy artillery against civilians.
The UN, which helped organise the elections, said Mr Ouattara won, but Mr Gbagbo refused to accept defeat.
In other developments:
- The UN human rights office has confirmed the deaths of 536 people during recent fighting in western Ivory Coast; it has named a panel to investigate
- The Reuters news agency reports that 14 bodies were found in the pro-Gbagbo area of Yopougon
- Former colonial power France has announced it will give Ivory Coast 400m euros ($575m; £350m) in emergency aid.
Our correspondent says some Abidjan residents are still too afraid to leave their homes in case they are caught by gunmen.
Many residents have been trapped for days by the fighting.
Some pro-Gbagbo troops may have refused to surrender, or the shooting could be coming from some of the thousands of Gbagbo supporters who were given weapons to fight the pro-Ouattara forces, our correspondent says.
There are also reports of reprisal killings and there are hardly any police on the streets.
Our correspondent says the only robust and well organised force the new president can count on are the UN and French forces.
The pro-Ouattara forces, who swept down from their northern strongholds earlier this month, include army defectors, as well as ethnic militiamen and traditional hunters, who may not always obey orders or respect military discipline, analysts say.
An end to the insecurity would allow markets to re-open and people to return to their homes.
For life to return to normal, banks must also open.
They have been closed for more than two months because of financial sanctions imposed on Mr Gbagbo to try to force him from power.
Until a 2002 rebellion split the country in two, Ivory Coast was the most developed economy in West Africa and Abidjan was known as the "Paris of Africa".
Gbagbo son beaten
Speaking on his TV channel hours after Mr Gbagbo's capture, a sombre Mr Ouattara appealed to Ivorians to "abstain from all reprisals and violence".
"After more than four months of post-electoral crisis, marked by so many human lives lost, we are finally at the dawn of a new era of hope," he said.
Mr Gbagbo, his wife Simone and his "collaborators" would be investigated by the judicial authorities, Mr Ouattara said, adding that their personal security would be guaranteed.
Mr Gbagbo and his wife have been put under UN police guard at Abidjan's Golf Hotel, where Mr Ouattara has his headquarters.
Mr Gbagbo has been shown on pro-Ouattara TV sitting in a room, looking dazed but apparently uninjured, wearing an open shirt and white vest.
He called for an end to the fighting.
But French TV showed pro-Ouattara forces beating his son, Michel, and other Gbagbo supporters.