Kathmandu: Chaos prevailed at Nepal's only international airport here on Monday with hundreds waiting to be evacuated from the earthquake-ravaged country as India and other nations scurried to bring back their panic-stricken citizens.

While 2,500 people have been evacuated so far, scores of people, largely Indians were lined up at the Tribhuvan International Airport to board commercial and special defence aircraft to return home.

Given the huge rush, priority is being given to women, children and senior citizens and those injured.

"There is chaos inside the airport as well, people are fainting because of the anxiety and excessive stress. Most of these are Indians," said Ekta Adhikari, a doctor at the Kathmandu Medical College.

"Until now, 2,500 Indians have been evacuated. Yesterday 15 flights ferried Indians trapped in the country, the exercise will continue till most of these people are evacuated," Prabhat Singh, a senior official of the Indian High Commission, said.

"M17 Indian choppers have been pressed in to evacuate people from the inner parts of Sindhupal Chowk, Gorkha and Nuwakot districts. Rescue operations in Bhaktapur and Kathmandu are also being carried out by the Indian authorities," he said.

Almost everybody waiting outside the airport had some harrowing experience to narrate.

Fayyaz Alam, a youth in his early 20s who hailed from Kishanganj, Bihar, and working in Kathmandu as a tailor, was there waiting with his heavily pregnant 20-year-old wife and his two brothers to be evacuated.

"After the earthquake, I don't find this place safe for my pregnant wife so we all have decided to leave for India," he said.

However, due to the heavy backlog of those waiting to return to India, the high commission authorities at the airport maintained that only his wife and one more person can be ferried for now.

Abdullah Mollick, a saree trader who has been doing his business in Kathmandu since the last eight months, was also in queue to get evacuated.

There were others who were frustrated over the waiting time and vented their ire on the authorities.

"There is no coordination here. Ideally the Indian government should have accommodated these people at the airport somewhere like the other embassies have done here. We were not allowed to enter the Indian High Commission, how will we come to know about the evacuation exercise carried out by the government," said Aditya Mehra, an Amritsar-based businessman.

Other countries too have deployed special aircraft and are working with local authorities to evacuate their nationals.

Michael Toma, a Czech tour operator, was looking for Czech nationals so that they could be evacuated.

"We have around 22-25 Czech nationals in Nepal. Our counsellor in Nepal and our ambassador in Delhi are here coordinating the rescue," he said.

The plane traffic became so congested that numerous flights were turned away on Sunday and forced to return later.

Luggage handlers stacked their carts high with suitcases and baggage from flights arriving from New Delhi, Muscat and Istanbul.

The number of passengers hoping to depart far outnumbered those arriving, but the baggage claim hall was stuffed with travellers.

The marble floor, cracked by the earthquake, was covered with travellers napping against walls and slumping against pillars.

The airport is about six kilometres from the city centre, in the Kathmandu valley. It is the sole international airport in Nepal and has served as an airfield since 1949.

A state of emergency has been declared in Nepal after a powerful 7.9-magnitude earthquake struck the country on Saturday followed by over a dozen aftershocks. Over 3,700 people have been killed and nearly 7,000 others injured in the tragedy.