Mali's President Ibrahim Boubacar Keita said he had launched an investigation into violence committed during a mass anti-government protest on Friday, which saw at least one person killed and 20 wounded.

Thousands initially rallied in the capital city Bamako to demand that Keita resign over a long-running jihadist conflict, economic woes and perceived government corruption in the fragile West African state.

But the protest later descended into violence -- a rare occurrence in the capital -- as demonstrators blocked main thoroughfares, attacked the parliament and stormed the premises of the state broadcaster.

"We have recorded one death," said Yamadou Diallo, a doctor in Bamako's Gabriel Toure hospital, adding that 20 people had been wounded.

An official from the prime minister's office also confirmed the death.

The circumstances under which people were wounded and one person was killed were not immediately clear.

The protest, organised by a new opposition coalition, is the third such demonstration in two months -- significantly escalating pressure on the 75-year-old president.

Led by influential imam Mahmoud Dicko, the so-called June 5 movement is channelling deep-seated frustrations in the country.

Under pressure: Malian President Ibrahim Boubacar Keita, pictured at a Sahel summit in the Mauritanian capital of Nouakchott on June 30
Under pressure: Malian President Ibrahim Boubacar Keita, pictured at a Sahel summit in the Mauritanian capital of Nouakchott on June 30 POOL / Ludovic MARIN

The opposition alliance said in a Friday evening statement that, pending further details, it held the government responsible for the violence.

It also urged security forces to protect "the bare-handed protesters who are only defending democratic, secular and republican values".

Keita, in a statement on Friday evening, said the scale of "human and material losses" remained unclear but that an investigation was underway.

He also bemoaned the violence and suggested that some opposition leaders had incited it.

Friday's demonstration came after the president unsuccessfully floated reforms intended to appease opponents this week, having rejected their calls to dissolve the parliament and form a transition government.

Many protesters on Friday carried placards bearing anti-government slogans and blew vuvuzela horns, AFP reporters saw.

"We don't want this regime any more," said one of the demonstrators, Sy Kadiatou Sow.

Protesters in Bamako block two of the city's main bridges during a protest against President Ibrahim Boubacar Keita which saw one person killed and some 20 hurt
Protesters in Bamako block two of the city's main bridges during a protest against President Ibrahim Boubacar Keita which saw one person killed and some 20 hurt AFPTV / Malick KONATE

Protesters later erected barricades and set tyres alight on two of the main bridges in the city, AFP journalists said, and entered the courtyard of state broadcaster ORTM, whose television channels later went off air.

National guardsmen also fired tear gas at demonstrators hurling stones at the parliament building.

Such unrest is rare in Bamako, which has been spared much of the violence that is routine across swathes of Mali.

The country has been struggling to contain an Islamist insurgency that first emerged in the north in 2012, before spreading to the centre of the country and to neighbouring Burkina Faso and Niger.

Thousands of soldiers and civilians have been killed and hundreds of thousands of people have been forced from their homes.

On Friday, opposition leaders published a ten-point document calling for civil disobedience.

Recommendations in the document included not paying fines, blocking entry to state buildings, and occupying crossroads.

After weeks of growing political tension, Keita had made a speech on Wednesday in which he offered to appoint new judges to the constitutional court.

The court has been at the centre of controversy in Mali since April 29, when it overturned provisional results for March's parliamentary poll for about 30 seats.

That move saw several members of Keita's party elected and triggered protests in several cities.

It is also widely seen as having ignited the country's latest political crisis.

Keita, who was first elected in 2013, had suggested that appointing new judges would mean the constitutional court could revisit its earlier decision.

But the speech fell on deaf ears among Mali's opposition leaders, who had been demanding that the president dissolve the parliament and form a transition government.

Issa Kaou Djim, a member of the political opposition, said that efforts at dialogue had failed.

Keita is on increasingly shaky political ground as protests continue, alarming the international community which is keen to avoid Mali sliding into chaos.