Yemen

 Yemen's Iran-backed Huthi rebels on Tuesday threatened retaliation against the ports and airports of the United Arab Emirates and Saudi Arabia, which this week closed Yemen's land, sea and air borders.

"All airports, ports, border crossings and areas of any importance to Saudi Arabia and the UAE will be a direct target of our weapons, which is a legitimate right," read a statement released by the rebels' political office. 

A military coalition led by Saudi Arabia has been battling the Huthis in Yemen since 2015.