The propaganda chief of Al Qaeda in the Arabian Peninsula (AQAP)was among six militants killed in two separate US drone strikes in Yemen, tribal sources said on Thursday.

The Wednesday evening strikes came as Washington revealed that US forces have carried out more than 120 air strikes against militants in Yemen this year as part of a long-running campaign that has intensified since United States President Donald Trump took office.

Saudi-born Abu Hajar al-Makki and three other AQAP militants were killed when a drone blew up their vehicle in the Wadi Obeida district of Marib province, east of the capital Sanaa, tribal sources said. A separate strike on a second vehicle killed two other AQAP militants in the same area, they added.

Washington says its strikes have killed a number of senior AQAP figures in recent months, including Mujahid al-Adani, who was killed on November 20.

It considers AQAP to be the worldwide militant network's most dangerous branch.

The extremist group has thrived in the chaos of nearly three years of civil war between the government and rebels who control the capital.

In addition to the air strikes, mostly carried out by drones, US special forces have conducted a number of ground raids against AQAP. The Pentagon has also been attacking a local branch of the militant Islamic State group, which it says has doubled in size over the past year.