Four people have been killed in protests in the Democratic Republic of Congo over claims that President Joseph Kabila is seeking to extend his 14-year rule by delaying next year’s elections.
Protests continued on Tuesday in the capital, Kinshasa, following Monday’s fatal clashes between opposition supporters and security forces.
Protesters say government plans for a census are a ploy to delay elections.
Mr Kabila is constitutionally barred from contesting the poll.
The government admits the poll could be delayed, but says the census is vital to ensure free and fair elections.
The BBC’s Maud Julien reports from Kinshasa that most shops are closed and internet and telephone connections have been blocked.
Hundreds of angry young men are burning tyres in several neighbourhoods, looting shops and throwing rocks at cars, our reporter says.
In the poor area of Masina on the city’s outskirts, police tried to disperse protesters by shooting into the air, she adds.
Government spokesman Lambert Mende said two policemen and two “looters” were killed in Monday’s clashes in Kinshasa.
Demonstrators called on Mr Kabila to step down when his term expires and carried placards which said: “Don’t touch the constitution”.
Hundreds of people protested also protested on Monday in Goma, the main trading post in the east.
The protests coincided with a debate in the Senate, the upper parliamentary chamber, over government plans to hold a census before elections.
The lower chamber, the House of Representatives, approved the plan on Saturday, in a vote boycotted by opposition MPs.
The opposition says this amounts to a “constitutional coup” by Mr Kabila, as it will take about three years for a census to be conducted in DR Congo, which is two-thirds of the size of western Europe, has very little infrastructure and is hit by instability in the east.
DR Congo, formerly known as Zaire, has never had a reliable census since independence from Belgium in 1960.
Mr Kabila took power in 2001 following the assassination of his father Laurent Kabila, who was president at the time, and has won two disputed elections since then.
DR Congo is rich in resources, but most people are poor.