Burkina Faso President Blaise Compaore has imposed a state of emergency after violent protests at his bid to extend his 27-year rule.

The government and parliament have been dissolved, and an overnight curfew has been declared across the country.

Protests to demand Mr Compaore's resignation are continuing in the capital, Ouagadougou.

Angry crowds had earlier set fire to the parliament and other government buildings.

This forced MPs to abandon a vote aimed at allowing Mr Compaore to seek re-election in 2015.

The main opposition leader, Zephirin Diabre, told a local radio station that the state of emergency was unacceptable.

"We are calling on the people to show that they are against it. The resignation of President Blaise Compaore is the only thing that can bring peace to the country," he is quoted as saying.

Mr Diabre said dozens of protesters had been killed across the country by the security forces.

It was a "barbaric escalation of violence", he said.

The military fired live bullets to try and disperse protesters who had occupied parliament, our correspondent says.

Protesters had also surged towards the presidential palace, and a government helicopter flying overhead fired tear gas at them, Reuters news agency reports.

Witnesses say dozens of soldiers have joined the protest in Ouagadougou's main square, including a former defence minister, Gen Kouame Lougue.

Protesters are demanding his installation as president.

The city hall, the homes of MPs, and an upmarket hotel in Ouagadougou were also set ablaze.

Similar protests hit the south-western city of Bobo Dioulasso, and other towns in the poor West African state.