An alarming increase in deadly jihadist attacks has led to expanded French military action in Burkina Faso, a marked shift after years of reticence by the west African nation to call in help from its former colonial master.Until now France's 4 500-member Barkhane anti-terror force in West and Central Africa has intervened mainly in Mali, while focussing on training in Burkina Faso and the other nations of the G5 Sahel military alliance - Chad, Mauritania and Niger.But over the past two weeks, more than 20 members of Burkina Faso's security forces have been killed in the country's restless north and east.After rebels raided a police station in the north last week, officials asked Barkhane's command for air strikes, which killed around 10 of the attackers as they fled.It also deployed two attack helicopters to the suspected rebel haven in the heavily forested Pama region last weekend after a Burkinabe soldier was killed by an IED, military sources said.The new theatre for operations highlight the challenges facing France as it tries to contain the jihadist threat in the region, which has taken a toll on economic growth and helped fuel the wave of migrants fleeing toward Europe.Paris's strategy has been based on trying to build up local African forces in the stuttering G5 Sahel alliance, but the growing instability in Burkina now looks likely to draw its troops into more frontline fighting.French Defence Minister Florence Parly sought to put a positive spin on the prospect of deeper French involvement last week during a visit to Chad."A pragmatic and constructive step has been taken," she said. New strain? The new front could put further strain on the Barkhane force, whose command was taken over two months ago by General Frederic Blachon. Yet officials are playing down such risks for now, pointing to the rapid air responses possible from the Barkhane air base in Niger's capital of Niamey."A plan can be adapted," Blachon said recently, adding that Burkina Faso's government "will have the same support that we give to others in the G5.""We always maintain sufficient intervention capacity to lend support" outside Mali, a senior military officer said in Paris, requesting anonymity to discuss military strategy.Burkina's requests for help underline the worsening security situation in the country due to the state of the country's armed forces and the difficulty in containing numerous armed jihadist groups operating in the region.Since the 2014 ouster of Burkina leader Blaise Compaore, who used elite forces as his personal guard, the government has been wary of giving the military too big a role in a country scarred by several coup attempts.But the attacks are now jeopardising President Roch Marc Christian Kabore's vow to improve security, education, health and drinking water in the country's Sahel region.French officials have made no secret of their concerns about the violence, and the risk of contagion to countries further south like Ghana and Ivory Coast. Special forces Paris has for years stationed special forces in the Burkina capital Ouagadougou, who intervened after twin attacks last March on the French embassy and Burkina's military headquarters which left eight soldiers dead.That attack was claimed by the Group to Support Islam and Muslims (GSIM), one of several prowling across the vast desert expanses of the Sahel.But French forces are still trying to identify the insurgents operating with increasing boldness in the country's east."It appears they are not with Ansarul Islam," a jihadist group based in the country's north which has carried out several attacks against the army along the 1 000km border with Mali, a Barkhane intelligence officer said."But we don't yet have enough information about how many there are, or where they're coming from," he said.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook.