An immigration official stopped the Nepal Airlines plane just before take-off following a tip-off that some passengers had illegally boarded the aircraft, according to officials.
Janak Rai, Amrita Lama, Soni Rai and Anusha Tamang, all Nepalese-origin Indian nationals, were about to fly to Hong Kong illegally by using tourist visas when they were arrested.
They had reached Kathmandu from India by road.
According to the existing rules, any Indian national wising to visit a third country via Nepal needs to get a no-objection letter from Indian Embassy in Kathmandu.
The four persons were travelling to Hong Kong with illegal travel documents with the help of human traffickers, an Immigration Department official said.
In the recent past, there have been several attempts of trafficking Indian labourers to the Gulf countries via Nepal through illegal channels in collaboration with some immigration officials.