Aden--Washington warned Thursday it would not stand by while Tehran supports rebels in Yemen, as Iran's supreme leader denounced Saudi-led air strikes as "criminal acts".
In the most direct American criticism yet of Tehran's backing for the Shiite Huthi rebels, Secretary of State John Kerry said Washington would not accept foreign interference in Yemen.
"There have been -- there are, obviously -- flights coming from Iran. Every single week there are flights from Iran and we've traced it and know this," Kerry told PBS television.
"Iran needs to recognise that the United States is not going to stand by while the region is destabilised or while people engage in overt warfare across lines, international boundaries in other countries."
Washington has backed the air campaign which begin last month as the rebels advanced on Yemen's main southern city of Aden after seizing Sanaa.
Iran's Ayatollah Ali Khamenei warned that the campaign against the Huthis must end.
"This move is not acceptable in the region and I would warn that they must stop these criminal acts in Yemen," he said on his website.
President Abedrabbo Mansour Hadi fled Aden for Saudi Arabia during the Huthi advance and the city has since seen heavy clashes between pro- and anti-government forces.
Riyadh has accused Tehran, the major Shiite power, of backing the rebels in a bid to establish a pro-Iran state on its doorstep.
But Iranian Foreign Minister Mohammad Javad Zarif insisted Tehran wanted a swift end to the fighting which has killed more than 640 people since March 19, according to the World Health Organization.
The UN children's agency warned Thursday that around 30 percent of fighters in Yemen's armed groups were minors.
"We are seeing children in battle, at checkpoints and unfortunately among (those) killed and injured," Julien Harneis, UNICEF's representative in Yemen, told AFP during a stop in Geneva.
AFP
