A five-nation African anti-terror task force vowed on Saturday to press on in its battle against jihadists, the day after a suicide attack on the outfit's headquarters in Mali killed two soldiers and a civilian.Friday's attack was carried out by a bomber in a vehicle painted in UN colours who destroyed the building's entrance wall.It was the first attack on the headquarters of the G5 force, set up with the backing of France in 2017 to roll back jihadist insurgents and criminal groups in the vast, unstable Sahel region.The Al-Qaeda-linked Support Group for Islam and Muslims, the main jihadist alliance in Africa's Sahel region, claimed the attack in a telephone call to the Mauritanian news agency Al-Akhbar."The conditions of this force will improve," Mauritanian Foreign Minister Ismail Ould Cheikh Ahmed said."This shows our determination rather than an indication of any weakness."French President Emmanuel Macron and his Cameroonian counterpart Paul Biya on Friday condemned the attack and discussed the security situation in the Lake Chad area, the French leader's office said on Saturday.The strike came three days before a meeting in the Mauritanian capital Nouakchott between Macron and the heads of the G5 Sahel states to discuss progress made by the force. Four suspects arrested The G5 Sahel aims to have a total of 5 000 troops from five nations - Burkina Faso, Chad, Mali, Mauritania and Niger - but has faced funding problems.It operates alongside France's 4 000 troops in the troubled "tri-border" area where Mali, Niger and Burkina Faso meet, and alongside the UN's 12 000-strong MINUSMA peacekeeping operation in Mali.In a telephone call on Friday, Macron and Biya discussed "the need to continue with regional cooperation in the fight against terrorist acts by the Boko Haram group," the French statement said.The strike in the Malian town of Sevare came shortly after Friday prayers, a military source in the G5 Sahel force told AFP.Governor Sidi Alassane Toure said four suspects had been arrested.Mali's President Ibrahim Boubacar Keita, in Sevare on Saturday, promised to "hunt down the terrorists" who carried out the attack, assuring it will not "deflect us from our objective." UN secretary general Antonio Guterres condemned "the complex attack perpetrated against the G5-Sahel Joint Force's Headquarters", his spokesperson said.Guterres, who visited the Sevare headquarters last month, highlighted security shortcomings on several of the force's sites in Mali in a report published in May."Poor conditions on and around the site represent an important security threat, and are delaying the deployment of the remaining soldiers," the report said. 'Huge blast' Residents in Sevare, 600km northeast of the capital Bamako, hid inside their homes during the attack, according to Bouba Bathily, a trader who sheltered from the gunfire in his house.A local orange seller, Haoussa Haidara, said "there was a huge blast" followed by shooting that lasted more than an hour.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook. The G5 Sahel was scheduled to be fully mobilised by mid-2018, but its deployment has faced delays, equipment worries and accusations of human rights abuses.On Tuesday, the UN said Malian soldiers within the force had "summarily" executed 12 civilians in a market in central Mali in May in retaliation for the death of a soldier.France intervened militarily in Mali in 2013 to help government forces drive Al-Qaeda-linked jihadists out of the north. But large tracts of the country remain lawless despite a peace accord signed with ethnic Tuareg leaders in mid-2015 aimed at isolating the jihadists. The violence has also spilled over into both Burkina Faso and Niger.