US
Iran-backed Houthi rebels' partnership with powerful ex-president Ali Saleh appears to have fallen apart
Saleh stepped down from office in 2012 but remains leader of country's largest political party
The attack was allegedly carried out by rebels from Yemen late Thursday night
May met both King Salman and powerful Crown Prince Mohammed bin Salman on a brief visit to Riyadh
Aden has been hit by a spate of bombings that have killed hundreds of people, some claimed by Al-Qaeda and some by IS
London-based AOHR says UAE has used cluster bombs and hired mercenaries to carry out torture and executions
Al-Qaeda's jihadist rivals, the Islamic State group, have also carried out several deadly attacks in the country
More than 2,000 people have died of cholera in Yemen this year
Despite tensions flaring, analysts are not convinced that an all-out war will take place yet
Capital Sanaa and al-Bayda join list of 5 cities lacking water