The conflict in the Arab world's poorest nation began with the 2014 takeover of northern and central Yemen by Iran-aligned rebels, driving out the internationally recognized government from the capital, Sanaa. Months later, in March 2015, a Saudi-led coalition launched its air campaign to prevent the rebels, known as Houthis, from overrunning the country's south.
Saudi-led airstrikes have hit schools, hospitals and wedding parties and killed thousands of Yemeni civilians. The Houthis have used drones and missiles to attack Saudi Arabia and have targeted vessels in the Red Sea.
Civilians have suffered the most in the conflict, which has created what the United Nations says is the world's worst humanitarian crisis. ACLED said approximately 20,000 people have been killed this year, already making 2019 the second-deadliest year on record after 2018, with 30,800 dead.
The non-governmental organization said April was the most lethal month so far this year, with over 2,500 reported killed, compared to approximately 1,700 in September. It said up to 1,100 civilians have been killed so far in 2019, with targeted anti-civilian violence was centered in the provinces of Dhale, Hodeida, Hajjah and Taiz.
The project said the Saudi-led coalition and its allies were responsible for more than 8,000 deaths resulting from the direct targeting of civilians since 2015, and the coalition airstrikes caused around 67% of all reported civilian deaths.
ACLED said that although the number of Saudi-led coalition airstrikes is at an all-time low, civilian fatalities from air raids have risen for the first time since the end of 2017, more than doubling in the third quarter of 2019, compared to the previous quarter, primarily due to a strike on a prison facility in Dhamar province that killed at least 130 detainees.
The group said it recorded over 19,000 people killed in the southwestern province of Taiz since 2015, making it the most violent province in Yemen, largely due to a four-year siege by the Houthis, the group said.
Hodeida and Jawf followed Taiz as the next most violent provinces, with more than 10,000 total reported killed in each region since 2015, according ACLED. The data covers everything from airstrikes, shelling and ground battles between the various forces to militant bombings and violence at protests. But their numbers do not include those who have died in the humanitarian disasters caused by the war, particularly starvation.
The group, which receives funding in part from the U.S. State Department and Dutch Ministry of Foreign Affairs, builds its database on news reports from Yemeni and international media and international agencies.