Several thousand people marched in Mali's capital Bamako on Thursday to call for armed intervention by a West African regional force to help wrest back the vast north of the country from armed Islamist groups.

The demonstrators carried banners and placards supporting the Malian army, Prime Minister Cheick Modibo Diarra and the Economic Community of West African States (ECOWAS), which is preparing to send troops if it gets the backing of the United Nations and Western countries.

The rally in the city centre came as France and its United Nations partners pressed ECOWAS and the African Union to come up within 30 days with proposals to reconquer Mali's north, an area the size of Texas or France.

Additionally, according to European Union sources and a document obtained by AFP on Thursday, the EU is working on plans to help Mali's army, including the dispatch of 150 trainers.

"We have an ungoverned space under the control of terrorists, with narco-trafficking and smuggling of all kinds," an EU official said. "A credible threat of force -- that is what is lacking."

At the Bamako rally, protesters urged Captain Amadou Haya Sanogo and other troops to the front lines. Sanogo led the March 22 coup that toppled president Amadou Toumani Toure and caused chaos, opening the way for the Islamists, including Al-Qaeda in the Islamic Maghreb (AQIM), who are applying hardline Islamic sharia law in northern cities under their control.

Sanogo ceded power in April, but remains influential in Bamako, where his men are accused of many human rights abuses.

"The place of the soldiers is at the front, all the military must go there," one demonstrator said.

Another said, "I back the Malian army, the arrival of ECOWAS troops, I want intervention."

Many marchers emphasised the secular nature of the sub-Saharan country, criticising Islamists for their radical stance and for punishments they have meted out to civilians, such as death by stoning for an unwed couple and amputations for theft.

Other slogans and banners targeted Tuareg rebels of the separatist National Movement for the Liberation of the Azawad (MNLA), which launched an offensive in the north in January.

At first allied to the Islamists, the MNLA was swiftly overpowered and sidelined by them.

Some banners said there should be "No independence, no self-determination" for the Tuaregs, after the MNLA initially proclaimed independence in northern Mali before the Islamists took over. Demonstrators stressed the unity of the country.

"If nothing is done in coming days, the existence of our country will be in danger," said a statement by march organisers.

"To fail to help Mali will be a serious error on the part of the African and international community in the face of history ... a crime of non-assistance to a people in danger," the text added.

A draft resolution proposed by France aims to bring about "detailed recommendations" and an "operational concept" ahead of any military operation in a sensitive part of Africa, amid fears that Mali could become a base for AQIM and traffickers of various kinds.

French President Francois Hollande said Thursday that diplomatic solutions had come up short, a day after UN Secretary General Ban Ki-Moon urged for dialogue.

"Dialogue with whom? With AQIM? Can you imagine there ever being any conversations that would be useful?" Hollande said in televised comments.

As France calls for military intervention to return the north to government control, EU nations are considering proposals that include sending scores of military trainers to whip the Malian military into offensive mode.

Bamako has officially called on the United Nations to hand down a mandate for an international force in Mali.

Canada's Foreign Minister John Baird meanwhile told reporters in Paris that he was worried Mali could go the way of Afghanistan.

"Terrorism is the great struggle of our generation," Baird said after meeting his French counterpart Laurent Fabius.

"We must not allow the same problems that the world allowed to happen in Afghanistan to show their face in the Saharan region and Mali," he said.