Holidaymakers have been plunged into travel chaos for the second time in a week after Heathrow Airport was forced to shut one of its tunnels. 

This morning, passengers are facing huge delays after a ‘technical fault’ caused a tunnel connecting to Terminals 2 and 3 to close. 

Roads leading to the airport are heavily congested due to the closure, causing some frantic passengers to dash down the highway with their bags to make their flights.

Other travelers described the situation as ‘complete chaos’, feeling as if they were experiencing ‘hell on earth’ and saying they were ‘running out of air’ after being trapped in a tunnel connecting the two busy areas.

Heathrow reported that the problem has been fixed, but there is ‘still congestion in the area’, and travellers are advised to ‘allocate more time for their journeys’.

‘Earlier this morning a technical issue caused the closure of the main road tunnel into Terminals 2 and 3. This issue is now resolved and the tunnel has reopened,’ the statement read. 

‘There is some congestion at the airport, and passengers are advised to allow extra time for their journey. We apologise for any inconvenience caused.’

It is the second incident to cause delays at the airport in just one week after an IT issue with a National Air Traffic Services (NATS) centre on Wednesday led to more than 100 cancellations of flight across the country. 

Desperate flyers have also been spotted sprinting down the motorway with their luggage in hand after a technical fault caused a Heathrow tunnel to close

A sea of passengers wait outside Heathrow Airport terminals two and three which have been closed today due to a ‘technical fault’

Dozens of vehicles can be seen gridlocked on roads leading up to the airport on Tuesday

The chaos has already caused panic for travellers on one of the busiest weeks of the summer holidays. 

One penned on X: ‘People running with their luggage in the roads. Shameful.’ Another added: ‘People running dragging cases on the motorway now. Find a solution!’

Others inside the airport said ‘confused, stressed’ passengers have been left with no idea ‘what is happening’ and complained that airport staff were not helping the situation. 

‘Hey @HeathrowAirport – do better!! Utter chaos today. No staff helping massive amounts of confused, stressed passengers,’ one user wrote. 

A fourth person said: ‘Been at Heathrow for an hour caught between the lifts and terminal tunnel and no one knows what is happening, this country is knackered.’ 

National Highways has also shared that the M4 Heathrow Spur entrance into the two terminals is closed and was causing ‘severe delays’ on the road. 

They posted to X: The #M4 Heathrow Spur (at J4) into T2 and T3 is being CLOSED. For access to #HeathrowAirport please use the #M25 J14 and head towards T5.

‘There are already severe delays on the spur road. Please allow extra time if heading to the airport this morning.’

Passengers queue inside Heathrow Airport after a ‘technical issue’ caused the tunnel to terminals one and two to close

Dozens of passengers are seen crammed inside the busy Airport. Some Other claimed they felt like they ‘were running out of air’ after getting stuck in an underground tunnel linking the two busy hubs

A statement released by the airport this morning on social media explained there was an issue causing a key route to Terminals 2 and 3 to be closed

National Highways has also shared that the M4 Heathrow Spur entrance into the two terminals is closed and was causing ‘severe delays’ on the road

Images of traffic filling the motorway were shared alongside the post showing long queues

Images of traffic filling the motorway were shared alongside the post showing long queues. 

It comes after an area of Heathrow Terminal 3 was cleared on July 25 while a fire alarm was investigated, which passengers said had caused huge waits for passport control.

The alert just after 11am led to the temporary evacuation being carried out by staff for safety reasons, which some travellers complained had led to two-hour queues.

Christina Warren, who had just arrived on a Virgin Atlantic flight, tweeted: ‘Landed at Heathrow an hour early but there was a fire alarm so the line for passport control is literally backed up literally the entire terminal because of a fire alarm going off.’

Natalie Berg, another passenger waiting at Heathrow after arriving from the US, added: ‘Nearly two hours and line has barely moved at Heathrow. Just been told immigration and baggage reclaim has now reopened so hopefully on the move soon.’

And a further traveller wrote: ‘Fire crews investigating incident in baggage hall at Heathrow T3 mean security border is currently closed. Very long queue already.’

A Heathrow spokeswoman previously told MailOnline: ‘Following an earlier fire alarm evacuation in parts of Terminal 3, the incident has now been stood down. We apologise for any disruption caused to journeys.’

Traffic built up on the motorway due to the tunnel into Terminals 2 and 3 being closed 

Passengers were later allowed into the baggage reclaim hall to collect their bags and get on their way.

The airport recently pledged to cut waiting times at airport security, too.

Heathrow promised that 95 per cent of passengers will pass through security in under five minutes by 2031.

The airport is also planning to redesign its terminals to improve the passenger experience by creating 70,000 sqm more space for travellers, reports The Times. 

Terminals 3 and 5 are also set to get more shops and restaurants while the airport has pledged that 99 per cent of bags will arrive in time due to new technology. 

The airport said the technology would mean that 1.25 million fewer bags ended up lost. 

Heathrow’s new plans will form part of a £10bn investment to upgrade the passenger experience at the major airport. 

While earlier this month, it unveiled its designs for a third runway.