Yemen, one of the Arab world's poorest countries, has been devastated by a war between forces loyal to the internationally-recognised government of President Abdrabbuh Mansour Hadi and those allied to the Houthi rebel movement. More than 7,600 people have been killedand 42,000 injured since March 2015, the majority in air strikes by a Saudi-led multinational coalition that backs the president.

The conflict and a blockade imposed by the coalition have also triggered a humanitarian disaster, leaving 70% of the population in need of aid. 

The conflict has its roots in the failure of the political transition that was supposed to bring stability to Yemen following an uprising that forced its longtime authoritarian president, Ali Abdullah Saleh, to hand over power to Mr Hadi, his deputy, in November 2011.

Mr Hadi struggled to deal with a variety of problems, including attacks by al-Qaeda, a separatist movement in the south, the continuing loyalty of many military officers to Mr Saleh, as well as corruption, unemployment and food insecurity. The Houthi movement, which champions Yemen's Zaidi Shia Muslim minority and fought a series of rebellions against Mr Saleh during the previous decade, took advantage of the new president's weakness by taking control of their northern heartland of Saada province and neighbouring areas.

Disillusioned with the transition, many ordinary Yemenis - including Sunnis - supported the Houthis and in September 2014 they entered the capital, Sanaa, setting up street camps and roadblocks.

In January 2015, the Houthis reinforced their takeover of Sanaa, surrounding the presidential palace and other key points and effectively placing Mr Hadi and his cabinet ministers under house arrest.

The president escaped to the southern port city of Aden the following month. The Houthis and security forces loyal to Mr Saleh then attempted to take control of the entire country, forcing Mr Hadi to flee abroad in March 2015.

Alarmed by the rise of a group they believed to be backed militarily by regional Shia power Iran, Saudi Arabia and eight other mostly Sunni Arab states began an air campaign aimed at restoring Mr Hadi's government. 

The coalition received logistical and intelligence support from the US, UK and France.