BAMAKO - Since the month of May, at least 20 people, among them Malian forces, UN peacekeepers and civilians working for the United Nations, have lost their lives in various terrorist acts in North and Central Mali.

Most security observers who spoke to Xinhua believe terrorist networks have changed their strategy after a period of calm.

It all began with the cold blood assassination of commander Mahamadou Camara, a military doctor, on the night of May 15 in Gao, northern Mali.

The latest attack occurred on May 31 when a camp of the UN mission in Mali (MINUSMA) was targeted during a night attack.

"The objective was simply to hit MINUSMA camp, create panic and then attack the United Nations Mine Action Service (UNMAS) camp that provides anti-mines services for the UN mission. This is a choice that was not accidental because ambushes using land mines have become the new strategy for terrorists for the last few months," a Malian security officer who did not wish to be named told Xinhua.

"Surprisingly, the upsurge in attacks began at a time when ex-rebel movements grouped under the Coordination for Azawad Movement and the Platform had decided to withdraw from the process of implementing the Mali peace agreement that was signed a year ago with the Malian government.

"This has strengthened the position of those who have always argued that there is a link between the supposed ex-rebels and the terrorist networks," said Kalidou Camara, an independent consultant on issues of geopolitics and security in the Sahel.

"Terrorist groups like Ansar Dine, the Al-Qaida in Islamic Maghreb (AQIM) and Al Mourabitoune continue to cause massive losses. They target the Barkhane which is the French military operation, MINUSMA and Malian forces. These groups get support from the local population as well as some groups that have signed the peace agreement," MINUSMA head Mahamat Saleh Annadif told the media after Tuesday's attack that left one Chinese peacekeeper dead and four others injured.

It has also been discovered that terrorists have returned with more force in central Mali, where a MINUSMA convoy was ambushed on May 26 along Tenenkou-Sevare road. Five Togolese peacekeepers were killed in the attack.

"The state is absent in this part of the country. And if public authorities do not return to this part of the country, I believe the worst is yet to come," Oumar Bathily, the mayor of the central region of Mopti said on Monday on a local radio.

"What is happening in Mopti region is very worrying. At a time when peace was coming to the North, war is breaking out in the central region. Our mission has become very difficult," Annadif admitted.

According to analysts, the responsibility for providing security in the North and in Central regions is shared between the government, armed groups and the international community which should concretize its support for Mali.

For instance, it is important to reinforce aerial surveillance of the territory and over the convoys. But Mali does not have the means to carry out this task.

"The upsurge of attacks demonstrates the incapacity of the state, international mediators as well as French and UN forces to manage the Malian crisis, despite the signing of the peace agreement," an African diplomat in Bamako who did not wish to be named told Xinhua.

"Expanding the mandate of MINUSMA so that it can start fighting against terrorists is a solution that the UN Security Council does not seem to see," the diplomat said.

Another security analyst, Fousseyni Camara, observed that given the current situation, it should be understood that "deterrence and interposition can only work in a war between two states and not in the fight against terrorism."

His view is shared by many experts who believe "there is need for more vigilance because it seems it is terrorists who always have an advantage over the forces fighting them."