Pakistan, which has yet to decide whether to offer military support to a Saudi-led campaign in Yemen, is flying jumbo jets to the Middle Eastern country to evacuate hundreds of nationals, a Defence Ministry official said on Sunday.
Saudi Arabia evacuated dozens of diplomats from Yemen on Saturday and the United Nations pulled out international staff after a third night of Saudi-led air strikes trying to stem advances by Iranian-allied Houthi fighters.
Pakistan TV has interviewed distraught nationals in Yemen who have pleaded for help, saying nothing was being down to rescue them.
"The Saudi civil aviation authorities had given us clearance to send our passenger planes to Yemen," a Defence Ministry official told Reuters.
"In the first step, two jumbo jets will be sent to Yemen on Sunday to bring back the Pakistanis."
A convoy of 600 Pakistanis was moving towards the Red Sea port of Hodeida, where "arrangements for their brief stay before their return journey to Pakistan have been made", Foreign Secretary Aizaz Chaudhry was quoted by media as saying.
Defence Minister Khawaja Asif told parliament on Friday Pakistan had made no decision on whether to give military support to the Saudi-led coalition, while pledging to defend Saudi Arabia against any threat.
"We have made no decision to participate in this war. We didn't make any promise. We have not promised any military support to the Saudi-led coalition in Yemen," Asif said.
Prime Minister Nawaz Sharif, in a telephone call with Saudi King Salman on Saturday, offered "all potentials of the Pakistan army", media quoted the Saudi Press Agency as saying.
Asif told Reuters there was no danger of Pakistan getting caught up in a sectarian war.
Pakistan has been plagued with sectarian violence for years, with militant Sunni Muslim groups targeting its Shia minority.
"So many minorities and sects live in Pakistan," Asif told Reuters. "Whatever assurances we give Saudi Arabia is to defend its territorial integrity, but I assure that there is no danger of us getting involved in a sectarian war."
Sharif has long enjoyed close relations with the Saudi royal family. After his second term as prime minister was ended by a military coup in 1999, he went into exile in Saudi Arabia.
Saudi Arabia last year loaned $1.5 billion to Pakistan to help Islamabad shore up its foreign exchange reserves, meet debt-service obligations and undertake large energy and infrastructure projects.