Pakistani activists march in support of the Saudi government at a protest in Quetta on Monday. Pakistan on Sunday evacuated more than 500 of its citizens from Yemen by jumbo jet and sent a naval frigate to rescue others stranded in the war-torn country, officials said.

Reuters/Islamabad

Pakistan will send troops to Saudi Arabia to give military support to a coalition of mainly Gulf states fighting Yemeni Houthi rebels, a senior government official said on Monday.

Pakistan - a regional ally of Saudi Arabia - would join a Saudi-led military coalition conducting air strikes against Shia Houthi forces, the official said.

The air strikes are targeting the rebels' southward advance on the port city of Aden, the last bastion of Saudi-backed president, Abd-Rabbu Mansour Hadi.

Pakistan's Defence Minister Khawaj Asif denied that the country had made a decision to send troops to Saudi Arabia, saying a delegation led by him and foreign policy chief Sartaj Aziz, would go to Saudi Arabia on Tuesday and then decide.

Saudi Arabia has not decided yet whether to send ground troops into Yemen but is keeping its options open, its ambassador to the US said on Sunday, but was committed to completing its air campaign.

Nuclear-armed Pakistan shares a long border with Iran and has a warm relationship with Saudi Arabia, Iran's main regional rival.

"We have already pledged full support to Saudi Arabia in its operation against rebels and will join the coalition," the Pakistani official said.

Trip delayed

The Pakistani delegation, led by Asif and Aziz, had been due to arrive in Saudi Arabia on Monday but delayed the trip at the request of the Saudis, the official told Reuters.

On Monday night, Aziz and Asif met Pakistan's military chiefs and Prime Minister Nawaz Sharif.

"Pakistan remains firmly committed to supporting the sovereignty and territorial integrity of Saudi Arabia in accordance with the aspirations of the people of Pakistan," a statement from Sharif's media office said.

"Pakistan stands committed to playing a meaningful role in arresting the deteriorating situation in the Middle East."

There are already about 750-800 Pakistani servicemen in Saudi Arabia but none are combat troops. On Monday, a Pakistani military spokesman said 292 Pakistani soldiers were meeting Saudi troops for annual, pre-scheduled military exercises.

Saudi and United Arab Emirates planes are leading the air attacks and alliance spokesmen have not confirmed whether any other Gulf Arab states are taking part in the strikes, although Qatar, Kuwait and Bahrain are members of the alliance.

Residents said ships believed to be Egyptian shelled a column of Houthi fighters trying to advance on Aden.

The US is providing intelligence support, and a Gulf diplomatic official said France was giving similar help.

Pakistan has already had small demonstrations both for and against military intervention.

Right-wing religious groups demonstrated last week vowing to defend Saudi Arabia. But some civil society groups and opposition politicians spoke against intervention, in the view that it could further inflame sectarian tensions at home.