US warns Iran over 'support' for Yemen Houthi rebels

US Secretary of State John Kerry has warned Iran over its alleged support for Shia Houthi rebels in Yemen.
He told PBS news that the US would support any Middle Eastern country that felt threatened by Iran, and would not "stand by" if Iran destabilised the region.
The US has stepped up support for a Saudi-led coalition against the Houthis, who drove the Yemeni president out of the country.
Tehran has denied accusations it is backing the rebels.
However, it reportedly despatched navy vessels to the Gulf of Aden, off Yemen, on Wednesday.
Navy commander Rear Adm Habibollah Sayyari told state media the move was made with the aim of "safeguarding naval routes for vessels in the region".
Kerry said it was clear Iran was aiding the Houthis: "There are obviously supplies that have been coming from Iran. There are a number of flights every single week that have been flying in."