Arab coalition air strikes have hit the presidential palace in rebel-held Sanaa, according to residents of the Yemeni capital.
The air strikes come after Saudi Arabia's air defences downed two Houthi-launched ballistic targeting southern Saudi Arabia, coalition spokesman Col Turki Al Malki said.
Eyewitnesses said fighter jets struck targets in Sanaa several times around midday on Monday. They say some of the strikes hit the presidency, located in the busy commercial district of Tahrir.
Although it is not clear if there were rebel leaders inside the palace at the time, Skynews Arabia reported that top Houthi leaders Mohammed Ali Al Houthi and Mehdi Al Mashat were targeted in the strikes.
Al Houthi is the number three on the Saudi's most wanted terrorists list, with a reward of $20 million offered in return for information on the President of the Houthi Revolutionary Committee. His death would mark the second highest ranking Houthi death since last month.
Before the Houthi takeover of Sanaa, Al Houthi was imprisoned by the Yemeni government following his return from what was believed to be a three-year stint training in Iran with the Islamic Revolutionary Guard Corps beginning in either 2004 or 2005.
The bounty on his head matches that offered for Abdul Malik Al Houthi, the leader of the rebel group, who hasn't been seen in public for the past three years and has left his remaining leadership to run rebel-held territories.
Salah Al Sammad, the Supreme Political Council leader and second-in-command, was killed last month in an air strike.
His replacement, Mahdi Al Mashat, is also believed to have been in the presidential palace.
Photos emerged on social media showing the three-floor presidency building in rubble with heavy damage to surrounding buildings in the city's busy Tahrir district.
While it is still unclear if the two rebel leaders were in the building, six were reported killed and dozens more injured by agencies.
Both Al Mashat and Al Houthi are believed to have been attending a meeting in the presidential palace during the strike.
Al Mashat does not feature on Saudi's 40 most wanted terrorists in Yemen list published last year. The appointment of such a low-ranking member has been interpreted as indicative of a crisis of trust and a thinning of the ranks among Houthi leadership.
Colonel Al Maliki said that the two missiles shot down on Monday were en route to the city of Najran where they would have targeted civilian areas.
Saudi Royal Air Defense forces intercepted both missiles, causing fragments of the projectiles to fall on residential neighbourhoods. No injuries or damage have been reported.
Mr Al Maliki said this latest attack pointed to Iran’s continuing role in supporting the Houthi militia with weapons. “It's a clear violation of UN Security Council resolutions 2216 and 2231," said the spokesman of the Arab coalition, referring to the UN's demands to end violence in Yemen and for Iran to stop supplying the Houthis with ballistic missiles. "The firing of ballistic missiles at populated cities and villages is contrary to international humanitarian law.”
It's the first missile attack since it was revealed that American special forces have been working with their Saudi Arabian counterparts in the ongoing battle against the Houthi rebels.
The New York Times reported last week that a team of a dozen Green Berets are stationed on the Saudi border with Yemen and have been tasked with helping to locate and destroy rebel missile caches and the sites from which they are launching missiles at Saudi Arabia.
Sanaa was seized by the Iran-backed rebels in 2015 who have since used the city as their base of operations.
The Arab coalition intervened in the Yemeni civil war on behalf of Abdrabu Mansur Hadi's internationally-recognised government.