More than four years after seizing the capital, the Houthis have consolidated their grip over large parts of Yemen.

Yemen has been torn apart by conflict since late 2014, when Houthi rebels, allied with troops loyal to former President Ali Abdullah Saleh, captured much of the country, including the capital, Sanaa.

A coalition assembled by Saudi Arabia launched an air campaign against the rebels in March 2015 to try to restore the internationally recognised government of President Abd Rabbu Mansour Hadi.

With logistical support from the US, the Saudi-UAE alliance has carried out more than 18,000 raids on Houthi-held areas in an attempt to reverse their gains.

More than 60,000 people have been killed in the fighting, millions of civilians have been forced from their homes and the impoverished country has been pushed to the brink of famine.

The Arab coalition’s campaign of air raids has devastated Houthi positions, ammunition depots and bases, but largely failed to pave the way for the recapture of Sanaa.