WASHINGTON — Thousands of travellers are stranded at airports across the US as flight cancellations and delays continue to wreak havoc amid a deadly winter storm.

By mid-afternoon eastern time on Tuesday, nearly 4,900 flights had been cancelled and over 4,400 delayed.

Over 60% of the cancellations were from hard-hit Southwest Airlines, which called off over 2,500 flights.

The chaos has left thousands of exasperated passengers sleeping in terminals as they search for solutions.

More than 3,500 flights scheduled to leave Wednesday have already been cancelled, according to flight tracking service FlightAware.

Southwest spokesperson Jay McVey on Monday said that the cancellations and delays had a cascading impact across the airline's network.

"We've been chasing our tails, trying to catch up and get back to normal safely, which is our number one priority, as quickly as we could," he said. "That's exactly how we ended up where we are today."

The US Department of Transportation (DOT) has said that it is "concerned by Southwest's unacceptable rate of cancellations and delays [and] reports of lack of prompt customer service."

In a tweet on Tuesday, US President Joe Biden said that his administration is "working to ensure airlines are held accountable" for disruptions. He urged that passengers check to see whether they are entitled to compensation.

Senator Maria Cantwell, the chair of the US Senate Commerce Committee, said that the committee will "be looking into the causes of these disruptions and its impact to consumers."

Southwest, for its part, has repeatedly apologised and said the disruptions caused by the winter weather are "unacceptable".

On its website, the airline said that it will honour "reasonable requests" for reimbursement for meals, hotel and alternate transportation for those who have had flights cancelled or delayed between 24 December and 2 January.

With flight cancellations and delays continuing, thousands of passengers have been left at airports across the country as they attempt to re-book flights or make alternative travel arrangements. Passengers in locations including Denver, Chicago and Washington DC reported hours-long queues to speak to customer service representatives.

One Southwest passenger, Talia Jones, told BBC US partner CBS that she was "beyond frustrated and hurt" after travel disruptions meant she was unable to see her father for the holidays.

"It's very disappointing," Ms Jones said.

At Chicago's Midway Airport - where Southwest is the primary airline - hundreds of bags were waiting to be claimed. Social media images from angry passengers showed masses of bags lined up or in piles near baggage carousels.

"It's been hell," Denzil Smothers, whose flight was cancelled, told CBS.

According to the DOT's website, most airlines will rebook passengers on the next flight to a passenger's destination, provided that space is available. Passengers who wish to cancel their trip entirely are entitled to a full refund, even in cases in which they purchased non-refundable tickets.

A number of major North American airlines - including Southwest, American and Delta - have waived change fees for passengers who rebook during the storm.

Since 22 December, nearly 20,000 flights have been cancelled across the US, according to FlightAware.

More than 60 people have so far been reported dead as a result of the winter storm, including at least 28 in Buffalo, New York. — BBC