Riots have broken out in Malawi's capital, Lilongwe, as opposition groups protest against President Bingu wa Mutharika's government.
The BBC's Joel Nkhoma in the city says protesters are burning barricades and have looted at least two businesses.
Police have retaliated by setting up roadblocks and firing teargas.
The trouble started after a court ruled on Tuesday that nationwide protests, called against the high cost of living, were illegal.
Our reporter says despite the ruling, protests are also taking place in the main commercial city, Blantyre, and the northern city of Mzuzu.
But the situation is most tense in Lilongwe, where angry crowds have been shouting, "Let him [Mr Mutharika] go", our reporter says.
He says police roadblocks have prevented protesters from entering the city centre, where all shops are closed and streets deserted.
The riots are taking place in three townships near Lilongwe - Biwi, Kawale and Nchesi, our reporter says.
A shop owned by an MP from the ruling Democratic Progressive Party (DPP) and a warehouse belonging to a businessman allied with Mr Mutharika have been looted, our reporter says.
In a late night ruling on Tuesday, High Court judge Chifundo Kachale granted an injunction that the nationwide protests - organised by a coalition of civil society groups - were illegal.
The demonstrations were called to protest against rising fuel prices, a shortage of foreign exchange reserves, alleged bad governance and poor international relations.
Last week, the UK cut direct aid to Malawi after a diplomatic spat with Mr Mutharika's government.
The UK accused Malawi of mishandling the economy and failing to uphold human rights.
The government recently passed an austerity budget, raising taxes to reduce dependence on aid.
Malawi is one of the poorest countries in the world, with an estimated 75% of the population living on less than $1 (60p) a day.