BAMAKO (Reuters) - Mali launched an operation aimed at flushing out suspected al Qaeda militants in the Sahara on Saturday and states in the region are preparing for a joint crackdown, military sources said.
A group called al Qaeda in the Islamic Maghreb (AQIM) is threatening to kill a British hostage, believed to be held in the region, on May 15 unless Britain releases a Jordanian Islamist it is holding in prison.
Mali's army sent three combat units from the northern town of Kidal to pursue a convoy of armed men spotted in the region close to its borders with Algeria and Niger, said the source, who requested anonymity.
"We are awaiting what comes out of it. We do not know whether they are Salafists or another armed group ... but we think they are Salafists," said the source.
The AQIM title was adopted when rebels with Algeria's Salafist Group for Preaching and Combat (GSPC) affiliated themselves to the al Qaeda network.
Mali and others in the region such as Algeria, Niger and Mauritania are trying to deflect pressure from Europe and the United States to tackle Islamist militant violence there.
It was not immediately clear whether the Malian operation heralded a wider offensive. However, a senior military source in Niger confirmed there were preparations for a joint effort.
"This is a about attacking head-on a joint problem, namely the presence of terrorists linked to al Qaeda in the Islamic Maghreb in this vast area," said the source.
The source, who requested anonymity, did not specify when any operation could be carried out but said Niger's army chief, General Moumouni Boureima, had recently traveled to Algeria to discuss planning with officials there.
"Algeria has supplied military aid to Niger and we would like it to do the same for us." The source said Mauritania could also take part in any joint crackdown.
AQIM has been waging a campaign of bombings and shootings, primarily along Algeria's Mediterranean coast.
A security crackdown has reduced its ability to mount attacks there, forcing it to switch its focus to the Sahara, with its vast spaces and weak government control.
It has claimed responsibility for kidnapping two Canadian diplomats and four European tourists in the past five months. The two diplomats and two of the tourists were released in Mali last month. The remaining hostages are the Briton and a Swiss.
Security experts say the British hostage is most likely being held in the thinly populated area in the Sahara along Algeria's borders with Mali.
Additional reporting by Abdoulaye Massalatchi in Niamey; writing by Mark John; editing by Robert Woodward