Dozens killed in Saudi airstrikes on Yemen

"Military action from outside of Yemen against its territorial integrity and its people will have no other result than more bloodshed and more deaths," he told Al-Alam TV.

"We have always warned countries from the region and the West to be careful and not enter shortsighted games and not go in the same direction as al-Qaeda and [the Islamic State group]."

The bombing campaign began overnight against Houthi targets and army units loyal to former president Ali Abdullah Saleh.

Britain has said that it supports the military operation in Yemen, named "Decisive Storm", but that any long-term solution to the country's woes must be political.

Storm hits Yemen

The first airstrike was launched in the early hours of Thursday morning, with Houthi air defences, surface-to-air missile sites, an air base, and four military planes "destroyed" in the assault, according to the Saudi Press Agency.

The Houthi-controlled health ministry said at least 25 were killed and 40 injured during the overnight raids.

Amnesty International, meanwhile, said that six children under ten were among the dead.

"This high toll of civilian deaths and injuries in these attacks raises concerns about compliance with the rules of international humanitarian law," said Said Boumedouha, deputy director of Amnesty International's Middle East and North Africa Programme.

"Saudi Arabian and any other armed forces carrying out airstrikes in Yemen are required to take all feasible precautions to spare civilians."

The attack comes after Houthi rebels and pro-Saleh special forces inched closer to the Aden hideout of the internationally recognised president, Abdrabbo Mansour Hadi.

The Houthis overthrew Hadi's government in January after taking over the capital in September.

Hadi was arrested by the Zaydi Shia militant group but managed to flee to the south where he has support. Since then, the Houthis have launched a military campaign in Yemen, and have reached the outskirts of Aden province.

Saudi Arabia is suspicious about the Houthi movement, and alleged Iranian support of the group. Iran, however, denies giving money or training to the Houthis.

In 2009, Saudi Arabia fought a border war with the Houthi movement, and Riyadh has been concerned by the militant group's recent advances in the country.

According to the Saudi press agency, the latest campaign was ordered by King Salman bin Abdulaziz, and is supervised by Defence Minister Mohammed bin Salman bin Abdulaziz.

Other ministries and leading royal figures are reported to be involved in the campaign, including the interior ministry.

The White House has announced that it is working closely with its Arab allies in Yemen.

Sudan is taking part in the military operation in Yemen. - Sudanese military statement

Riyadh announced that ten countries would be taking part in Houthi operations, including other GCC nations - with the exception of Oman - as well as Egypt, Morocco, Jordan, Sudan and Pakistan.

"Sudan is taking part in the military operation in Yemen," read an SMS message sent to journalists by the Sudanese armed forces.

Military alliance

Pakistan, a longtime ally of Riyadh, said that it was also examining a Saudi request to intervene in Yemen, reported AFP.

"I can confirm that we have been contacted by Saudi Arabia in this regard. This matter is being examined. That is all I have to say at the moment," said Tasnim Aslam, Pakistan's foreign office spokesperson.

According to the al-Arabiya news channel, the UAE has sent 30 fighter jets to Saudi Arabia, while Jordan pledged to send six military aircraft.

Al-Arabiya also mentioned that the alliance had ordered Yemeni airspace to become a "restricted area".

In a joint statement, the participating countries announced they had taken action "to protect Yemen from aggression by the Iran-backed Houthi militias".

Arab foreign ministers are due to meet today in Egypt's Red Sea resort of Sharm el-Sheikh.

"Airstrikes launched by Saudi Arabia primarily aim to prevent Houthi rebels from using airbases, fighter jets and missiles to attack Aden and other parts of Yemen," Yemeni Foreign Minister Riyadh Yassin told Reuters.

Yassin added that airbases under Houthi control were targeted in the strikes - al-Dailami, Taiz and al-Hadida.

Yemen's internationally recognised government had in recent weeks requested military assistance to stopping the advance of the Houthi rebels, while Saudi Arabia had also called for a no-fly zone.

The foreign minister did not say how long the military campaign would last, only that it would continue "until it achieves its goals".

Sources in Yemen say that a number of "sensitive" sites controlled by the Houthis in Sanaa were targeted, including a special forces barracks, where allies of Saleh were stationed.

Fires were reported to have broken out at the presidential palace in Sanaa while the political bureau of the Houthi militias was also said to be targeted.

In the south, Saudi airstrikes targeted the Houthi-controlled al-Anad airbase on Wednesday, according to locals.

Al-Masira television channel, run by the Houthis, stated "the Saudi-led air strikes launched on Thursday targeted a residential area north of Sanaa, causing dozens of deaths and injuries".

The location of President Hadi remains uncertain - but his office manager, Mohammad Marem, told Reuters that he was still in Aden and in high spirits with Saudi Arabia announcing its intervention.

"The operation restored the people's determination to fight the Houthis. It is primarily aimed against Houthi air defences in the north," Marem added.

Medecins Sans Frontieres continues to operate a surgical unit in al-Sadaqah hospital in Aden, where it is treating injured civilians and militia fighters alike.

"MSF is calling on all parties to keep the area of the hospital neutral and to ensure access to the hospital for the injured," read a statement from the charity group.

"MSF is also appealing to all sides to not enter the hospital with weapons, as this impedes medical activity and subjects medical staff and patients to risk."

This article is an edited translation from our Arabic edition.