The Islamic State Just Rocked Yemen with Suicide Car Bombs

The Islamic State group has claimed responsibility for a series of suicide bombings in the southern Yemeni port city of Aden on Friday that killed upwards of 20 people.

Three separate blasts, at least two of them resulting from car bombs, struck military checkpoints. Two explosions hit posts that guard the route to a base currently run by the Saudi-led coalition operating in Yemen, and that houses soldiers from the United Arab Emirates. Gunmen then attempted to assault the base, according to nearby residents. Coalition forces responded by firing on the militants from helicopters; it was unclear if those who attempted to attack the base had died.

The Islamic State's Amaq news agency later ran a bulletin claiming all three bombings and the assault. It said that at least 27 people were killed; local authorities cited by Reuters reported that at least 20 people had died, most of them civilians.

Saturday marks the first anniversary since the start of the US-backed and Saudi-led intervention in Yemen, which aimed to dislodge Shia Houthi rebel forces and fighters loyal to former President Ali Abdullah Saleh, with whom they are allied. Though the Houthis were driven from Aden, they remain in control of many of Yemen's major populated areas.

After initially fleeing to Riyadh, the government of Saudi-backed President Abd Rabbu Mansour Hadi has attempted to relocate temporarily to the port city. But according to diplomats, officials there barely move outside their offices out of fear that they could be targeted.

The Islamic State has struck Aden on several occasions, including a car bomb attack last year that killed the province's governor.

As the grinding and deadly war continues, Sunni extremist groups have gained ground.Al Qaeda in the Arabian Peninsula, the terrorist organizations affiliate in Yemen, has capitalized on a power vacuum to seize large areas in the country's south and west, including its third largest city, Mukalla.

On Tuesday, the US said that a military drone had struck a purported al Qaeda training camp in Hadramawt province, killing at least 70 militants. VICE News could not confirm that figure, or determine whether all of those killed were in fact members of al Qaeda. UN investigations have shown a heavy civilian toll from US drone strikes that have been aimed at the group's affiliate in Yemen.

More than 3,200 civilians have been killed in Yemen over the past year. Hundreds have fallen victim to the shells, mines, and bullets of the Houthis and their allies. But the UN estimates that the majority of those recorded deaths resulted from coalition airstrikes. During that time, the Saudi-led force has enjoyed uninterrupted intelligence and logistical support from the US, including the offloading of tens of millions of pounds of fuel from tanker planes to coalition jets over Saudi airspace.

On Wednesday, the UN announced that the main parties to the war in Yemen had agreed to a cessation of hostilities to begin on April 10 at midnight, to be followed a week later by talks in Kuwait. Unlike previous failed truces announced by the UN, this one appears to have resulted from direct communications between the Houthis and Saudis, and observers were cautiously optimistic in the following days.

But as Friday's deadly attacks showed, even if Yemen's main warring parties somehow agree to lay down arms and stop bombing, the extremist presence that has grown within the country is as virulent as ever before.

Follow Samuel Oakford on Twitter: @samueloakford