By PATRICK FORT

ABIDJAN - Jihadists are scoring gains in the Sahel, defying efforts by five countries in the fragile region to fight back with Western help against Islamist militancy.

Areas of insecurity on the Sahara's poor, arid southern rim are widening, analysts say, even as the so-called G5 Sahel group - Burkina Faso, Chad, Mali, Mauritania and Niger - seek to expand their anti-terror campaign.

"Overall, the security situation in the Sahel continued to deteriorate, having spillover effects on neighboring countries that are not members of G5 Sahel, including Benin, Cote d'Ivoire (Ivory Coast) and Togo," United Nations Secretary-General Antonio Guterres said this month.

Guterres said in recent months, armed groups had been sighted on Mauritania's border with Mali, attacks on security forces had continued unabated in Mali itself, "terrorist groups, militias and armed gangs" had proliferated in Burkina, and jihadists had killed dozens of soldiers and civilians in Niger.

At the end of last year more than 120,000 people had been displaced in Mali, a tripling in the space of a year, while 160,000 have fled their homes in Burkina.

According to a French military source, there are about 2,000 fighters across the Sahel, of which up to 1,400 are in Mali.

Their hallmark tactics - brutal gun attacks, roadside bombings and hostage taking - seek to weaken the rule of law and authority of the state, often fomenting intercommunal fighting on which they capitalize.

"There are not necessarily more attacks, but the attacks are more violent. The groups have acquired some technical competence," said Mahamadou Sawadogo, a researcher at the Crossroads of Study and Research for Democracy and Development at Senegal's Gaston Berger University.

"There's an increase in power at the quantitative level and also in their efficiency," noted Lassina Diarra, author of a book on West African countries facing transnational terrorism.

"In Burkina, there appears to have been a merger of means between groups affiliated to Al-Qaeda and those affiliated to the Islamic State," he said.

"It seems that they now lend each other a helping hand."

Diarra suggested that battle-hardened fighters may have arrived from the Middle East after the so-called Islamic State lost its territory in Syria.

"We are seeing changes in operational methods with the use of explosives, mines and car bombs" combined with more ambitious raids, he said.

Both academics showed concern at the weakness of regional armies, particularly in Burkina.

The problems facing the G5's armed forces are well known. Their militaries are under-equipped and poorly trained, even though governments are already earmarking as much as 15 percent of their budgets on security.

With support from France and others, the G5 countries are pushing ahead with plans for a pooled 5,000-man force.

But at present, they lack coordination in border zones, where jihadist forces are particularly active and whole populations become internally displaced. - AFP