Yemen’s former president, Ali Abdullah Saleh, was killed Monday after he appeared to switch sides against his former rebel allies and join with a Saudi-led military coalition, plunging the complex war into further chaos.

Mr Saleh held power for 33 years until he was ousted in 2011 but he remained a central figure in the country and spent two years battling alongside the Houthi rebels against Saudi Arabia and the man who replaced him as Yemen’s president.

The alliance between Mr Saleh and the Houthis collapsed last week and he began to make public overtures towards Saudi Arabia as his troops fought the Houthis in street battles in Saana, the rebel-held capital.

The 75-year-old former president was reportedly shot as he tried to flee the city and Houthi fighters joyfully paraded his bloody corpse before the cameras, much as Libyan rebels did after killing Muammar Gaddafi in 2011.

Abdul-Malek al-Houthi, the Houthi leader, said Mr Saleh had been killed for “treason” and warned the Saudi-led coalition they would not succeed in Yemen. "Today is the day of the fall of the conspiracy of betrayal and treason. It's a dark day for the forces of the coalition,” he said.