Hundreds of flights have been delayed and cancelled, stranded travellers have endured long waits and protesters have clashed with riot police in ugly scenes at Hong Kong’s international airport as demonstrations enter a second day.

Anti-government protesters began occupying the airport’s terminals on Monday, as part of wider demonstrations demanding greater democracy in the semi-autonomous, China-ruled city.

There were violent scenes overnight as riot police attempted to enter the airport and were driven back by protesters. Hardcore demonstrators attacked two men they claimed were Chinese spies.

Hong Kong’s political crisis began 10 weeks ago, when millions of people took to the streets to protest a now-shelved extradition bill that would have seen suspects sent to mainland China.

As anti-government fervour built momentum, the protest movement grew to include other demands, such as for an independent inquiry into police brutality and the release of arrested protesters, as well as anger against diminished freedoms and the growing influence of China.

The 10-week political crisis in Hong Kong is the biggest challenge to Chinese rule of the city since it claimed it from the British in 1997.

The protests at Hong Kong airport — one of the busiest in Asia, and a gateway to the continent — appears to be a tactical move by protesters trying to intensify pressure on the government by striking a critical economic asset with global significance.

Protesters blocked the departures and arrivals terminals, forcing the cancellation of hundreds of flights that are still backlogged since Monday. Protesters have been handing out pamphlets to arriving passengers that detail their anti-government message in multiple languages.

“We want to spread the message to them so that they can spread the message to their country,” student Peter Tan, 23, told the New York Times.

“We are trying to protect our rights and our city.”

But many travellers have been frustrated by lengthy delays and scenes of chaos at the airport.

“I really feel for the protesters. I think they’ve got a very good cause. But they’re doing their protest in the wrong place,” an Australian traveller told ABC News.

“They’re hurting innocent travellers like me, the elderly, little babies. They’re laying up there. They can’t sleep. They can’t get a feed. Conditions are deplorable.”

The Hong Kong government condemned the airport protests in a statement, saying “violent acts” by protesters were “are outrageous and have overstepped the bottom line of a civilised society.”

Hong Kong’s flagship airline Cathay Pacific was ordered by Chinese aviation authorities this week to ban staff who took part in protests from travelling to China.

This morning flight operations have slowly resumed at the airport, with check-in counters open despite dozens of protesters remaining camped out at the airport.