The state-owned Saudi Press Agency reports that the Yemeni nationals were living under aliases in Riyadh, where they were planning a suicide bombing along with two locals.
Security forces claim that the bombers were Daesh members, and two suicide belts as well as firearms, grenades, and other weapons were seized from their Riyadh hideout. While the names of the Saudis were not revealed to the press, the Yemenis were identified as Ahmad Yasser Al-Kaldi and Ammar Ali Muhammad.
In 2015, a Saudi-led coalition that also includes many Middle Eastern, African, and NATO states intervened in the Yemeni Civil War that pitted the government of Abdrabbuh Mansour Hadi against Houthi rebel groups allegedly backed by Iran, with the Daesh-affiliated AQAP as a third faction.
The Saudi military support for President Hadi has been denounced by the international community due to humanitarian violations by the Saudi military, such as blockading the Houthi-controlled city of Sana'a which has led to a cholera outbreak spreading to 600,000 people in a matter of months. At least 10,000 Yemeni civilians have been killed during the civil war.
The United Nations has called the Saudi intervention a "humanitarian catastrophe," a sentiment echoed by the European Commission, and human rights groups such as the Red Cross, Doctors Without Borders, Amnesty International, and Human Rights Watch.