NOUAKCHOTT: Al-Qaeda in the Islamic Maghreb has threatened to act "with firmness and determination" against anyone collaborating with a foreign military force that might intervene in north Mali.

Mokhtar Belmokhtar, a leader of AQIM, which is one of the armed Islamist groups controlling the huge territory for the past three months, warned Saturday that no one should be tempted to "profit from the situation" in north Mali "by collaborating with the foreign forces who are eyeing the region."

In a statement released by Mauritania's private news agency Nouakchott Informations (ANI), a mouthpiece for AQIM, Belmokhtar said: "We will not stand by with our arms crossed and we will act as the situation demands with firmness and determination."

On Friday another Islamist militant group in lawless northern Mali, the Movement for Oneness and Jihad in West Africa (MUJAO), threatened countries who would join a military intervention force.

Mali has been gripped by chaos since disgruntled troops swarmed the capital Bamako in the south in March and ousted the elected president of what had been seen as one of Africa's model democracies.

Tuareg rebels and Islamist hardliners have taken over a stretch of northern Mali the size of Afghanistan.

The Islamists, also including the Ansar Dine group, have since imposed an austere version of sharia law in northern Mali, and they have fallen out with the Tuareg.

The Economic Community of West African States, or ECOWAS, is considering sending a military force of 3,300 troops to Mali.

AQIM stems from a group started in the late 1990s by radical Algerian Islamists, who in 2007 formally subscribed to Al-Qaeda's ideology.

These Islamists, numbering around 300, have spun a tight network across tribal and business lines that stretch across the sub-Sahara Sahel zone, supporting poor communities and protecting traffickers.