A reported IT glitch at the immigration department has sent Bali's international airport into chaos, with commuters saying they have been stranded for hours on end while the situation is resolved.

Nine News said that hundreds of Australians, and possibly up to 2000 people in total, had been caught in long delays, with some waiting for up to five hours.

Reports from Indonesian news publications say the airport's traffic has increased nearly 5 per cent since this time last year. With almost 24 million passengers last year, it is the second busiest airport in Indonesia after Soekarno-Hatta International Airport in Jakarta.