Yemen rebels fired missiles at the United Arab Emirates and Saudi Arabia, with coalition forces hitting back by blowing up the insurgents' launchpad as a sharp escalation of hostilities entered a second week on Monday.
Witnesses saw bright flashes arcing over the Emirati capital Abu Dhabi in the early hours of Monday morning as two ballistic missiles were intercepted, scattering debris.
Nobody was hurt in the attack, which came a week after the Iran-backed Houthi rebels killed three people in a drone and missile assault on the city, triggering a volley of deadly airstrikes on Yemen.
Separately, missiles were fired on Saudi Arabia in southern regions bordering Yemen, with two people wounded in Jazan, and another missile intercepted over Dhahran al-Janub.
The UAE said an F16 fighter jet destroyed a Houthi missile launcher in Al-Jawf in northern Yemen at 4:10 am (0110 GMT), "immediately after it launched two ballistic missiles at Abu Dhabi".
It released a black-and-white video of the attack, showing an explosion followed by a large fire that sent up plumes of thick smoke.
'Expand the operation'
The UAE, part of the Saudi-led coalition fighting the Houthis, is "ready to deal with any threats" and was "taking all necessary measures to protect the state from all attacks", the defence ministry said.
The seven-year conflict, which has killed more than 150,000 and displaced millions, according to the United Nations, entered a dangerous new phase over the past week.
Coalition airstrikes on the Yemeni capital Sanaa and the Red Sea port city of Hodeida left at least 17 dead and knocked out the struggling country's internet.
At least 70 were also killed and hundreds injured in an attack on a prison, although the coalition denied responsibility.
After Monday's attack, the rebels threatened to ramp up their targeting of the UAE and repeated their warning for foreign companies to leave the oil, business, transport and tourism hub.
"We are ready to expand the operation during the next phase and confront escalation with escalation," rebel military spokesman Yahya Saree said in a televised statement.
He said the Houthis targeted Abu Dhabi's Al Dhafra airbase -- which hosts Emirati, US and French forces -- as well as "vital and important" locations in the Dubai area. The UAE did not report an attack on Dubai.
While the rebels have frequently attacked Saudi Arabia, the UAE is a new front in a conflict that also threatens the busy Red Sea shipping route.
Earlier this month, after being driven back by UAE-trained forces in a key province in Yemen, the Houthis hijacked a UAE-flagged ship in the Red Sea, saying it was carrying weapons.
But last week's Abu Dhabi attack -- the first deadly assault on UAE soil acknowledged by the Emiratis and claimed by the Houthis -- was a shock for the UAE, usually an oasis of calm in the volatile region.
Abu Dhabi lies about 1,500 kilometres (930 miles) east of Yemen's rebel-held capital Sanaa.
Reprisals were swift and severe. Fourteen people died in an air raid on Sanaa, and at least three children were killed in an attack on Hodeida that plunged the country into an internet blackout.
The coalition denied carrying out the strike on a prison in the northern city of Saada, the rebels' home base, that killed at least 70 people and wounded more than 100, overwhelming hospitals.
Aid agencies dismissed the coalition's denial, however, saying that witnesses in Saada heard fighter jets overhead followed by three loud explosions.
"This is the latest in a long line of unjustifiable airstrikes carried out by the Saudi-led coalition on places like schools, hospitals, markets, wedding parties and prisons," said Ahmed Mahat, head of mission for Doctors Without Borders (MSF).
Yemen's civil war began in 2014 when the Houthis seized Sanaa, prompting Saudi-led forces to intervene to prop up the government the following year.
The conflict has left millions on the brink of famine, according to the UN which calls it the world's worst humanitarian catastrophe.