The UK and US urged Yemen’s Houthi rebels to stop targeting Saudi Arabia on Wednesday, following an increase in missile and drone attacks targeting civilian population centres. A ballistic missile launched by the rebels targeting Riyadh was intercepted by the kingdom's air defence forces late on Monday. Residents said they heard a loud bang and videos on social media purporting to be from the city showed glowing orbs lighting up the sky as the missile was intercepted by surface-to-air Saudi missiles. “The Houthis have once again targeted<a href="https://twitter.com/hashtag/Riyadh?src=hashtag_click"> </a>Riyadh with ballistic missiles. Such attacks must stop, now,” James Cleverly, the UK’s Minister for the Middle East and North Africa, said in a statement. The UK will continue to support Saudi Arabia’s sovereign right to defend itself against such aggression, he said. “The Houthis and their reprehensible activity, their reprehensible behaviour, have helped unite the world against them,” Mr Cleverly said. His comments came as Washington condemned the continuous attacks. “We strongly condemn yesterday’s attacks by Houthi forces against Saudi Arabia that endangered civilians in and around Riyadh,” said State Department spokesman Ned Price. The attacks also “threatened Aramco facilities with unmanned aerial systems and ballistic missiles,” Mr Price said. In retaliation for the attacks, the Saudi-led coalition fighting the rebels in Yemen said on Tuesday it had launched air raids against targets in the country's capital Sanaa. The raids destroyed a Houthi missile launch site. Dozens of Yemeni citizens who had worked at the US embassy in Sanaa in a caretaker capacity since the embassy closed in 2015 were detained by the rebels last month. “The Houthis must immediately release unharmed all Yemeni employees of the United States, vacate the embassy compound, return seized property, and cease their threats,” Secretary of State Antony Blinken said on Twitter. The Houthis control much of northern Yemen, including Sanaa, which they seized in 2014. The Saudi-led coalition intervened in Yemen a year later to support the government, in a conflict that has left tens of thousands dead and millions displaced.