Mali's government is again trying to open a dialogue with rebels from the north of its vast country, where violence, cross-border hostage takings and the number of radical groups are escalating. Human rights activists say the government's use of military power to control the rebellions could be backfiring. VOA's Nico Colombant reports from our regional bureau in Dakar.

Malian officials and Tuareg rebels are expected to meet in Tripoli, Libya, to revive earlier talks that led to a deal between Mali's government and the main rebel group in late 2006.

A Malian delegation, including a high-ranking military official and an ethnic Tuareg community leader arrived in Tripoli, where rebel representatives are also expected.

A long lull in fighting, briefly broken in August 2007, was broken again on March 20 when ethnic Tuareg rebels clashed with Mali's army.

Several people were killed and dozens of Malian soldiers were taken hostage. Some security officials say the hostages may have been taken to nearby Niger, where there is also an active Tuareg rebellion.

Both rebellions say they are fighting for better allocation of resources and less military presence in their areas. Some rebel elements say they just want to make money.

On Wednesday, there were more clashes in northern Mali between suspected rebels and the army near the garrison town of Agueloc.

A man calling himself Ahmed, saying he represents a group called "Mezouk," claimed responsibility for the attacks. He said he was taking up arms for money.

London-based human rights activist Ibrahima Kane says despite international attention, instability in the vast, impoverished desert region seems to be growing.

"There are many rebel groups in that part of Africa. Some of them are supposed to have very strong links with al-Qaida, and there is lots of arms trafficking, many traffics in that part of the region," said Kane.

Al-Qaida's north African wing, al-Qaida in the Islamic Maghreb, is believed to be holding two Austrian tourists at a hideout in northern Mali.

The group is demanding freedom for several Islamic militants being held in Algeria and Tunisia, as well as ransom, according to Algerian officials.

Several Malian officials say they believe the hostages may have been moved to Algeria or Niger in recent days, because of the renewed violence in northern Mali.

A Tuareg expert and author on the subject, anthropologist Jeremy Keenan, does not believe there is a link between Malian rebels and al-Qaida.

"This is connected geographically but that is totally separate from this rebellion. In other words, the Tuareg rebellion and the Austrian hostage situation are not connected in any way. They just happen to be in the same area, but that is coincidental," he said.

He says links between different armed groups in the region do exist, such as between the Malian and Niger rebels, but they are difficult to define.

"The linkages are very, very complicated.... They involve a lot of history and quite detailed micro-politics and micro-sociology, and so forth but one thing I think I will probably say is the situation in Niger up until these last couple of weeks by and large has been worse than in Mali," he said.

Keenan says he believes the situation in both Mali and Niger has been aggravated by raids by government militaries on civilian areas. The two militaries have been receiving U.S. aid and training to combat terrorism and trafficking in the area.

The U.S. military says it is trying to help local governments do a better job of making their countries more secure and preventing remote areas from becoming bases for extremists.

But human rights activists have repeatedly warned that heightened militarization of desert areas with disaffected populations is fostering extremism and making the rebellions more popular.