A member of Ansar al-Sharia, also known as al-Qaeda in the Arabian Peninsula (AQAP), "ran a car and steered it towards a group of Houthis near a hospital that they had turned into their headquarters," the militant organization wrote in a statement.
"As a result of the attack, four trucks, three military pickups and two armored Humvees, used by the Houthis, were damaged," the statement continued.
The death toll from the explosion has reached 15, a representative of one of the Yemeni tribes told RIA Novosti. "Houthis have removed their dead from the explosion site," he said.
According to the source, a suicide bomber approached a group of Houthis in a car and carried out an explosion as they were having a gathering near a hospital in the Majzar district of Ma'rib Province.
"Houthis have been in control of the hospital for several days," the source said.
Earlier on Sunday, a bomb went off near a Houthis checkpoint in Yemen's capital Sana'a. According to witnesses, interviewed by RIA Novosti, the bomb exploded under a bridge 200 meters (650 feet) from the checkpoint. The explosion did not result in any casualties or injuries.
"Houthis surrounded the explosion site and barred people from approaching it," a witness said.
According to media records, Al-Qaeda had previously threatened to carry out attacks against Houthis in Sana'a and other regions.
The Houthis are a Shiite insurgent group operating in Yemen. Thousands of Houthi followers have in recent weeks staged anti-government rallies in Sana'a. According to Yemen's Health Ministry, at least 270 people were killed during last week's clashes between the government forces and followers of the Houthi movement.
On September 21, the sides signed an agreement to end days of fighting, but the rebels remain in control of much of Yemen's capital and continue to occupy a number of governmental buildings.