CNN  — 

Pakistan airspace remained closed Thursday morning local time as the country’s increasingly fraught tensions with India disrupted thousands of flights worldwide for the second straight day.

All international and domestic commercial flights in and out of Pakistan were canceled “until further notice,” Pakistan’s Civil Aviation Authority told CNN.

Thousands of people were also stranded by affected airlines that not only land in Pakistan, but fly over its airspace – one of the major routes from Southeast Asia into Europe.

Thai Airways announced that all its European routes “departing near midnight of 27 FEB through early 28 FEB” were canceled “due to sudden closure of Pakistani airspace as a result of tension between India and Pakistan.”

On Thursday morning, there were no Thai Airways flights between Bangkok and London, Munich, Paris, Brussels, Milan, Vienna, Stockholm, Zurich, Copenhagen and Oslo, the airline said in a statement.

By lunchtime Thai Airways had resumed “normal flight operations” to Europe “through airspace outside Pakistan’s,” the airline said. Thai Airways flights to Pakistan remain canceled, however.

Other airlines diverted or re-routed their flights and some had to make stops to take on extra fuel to complete extended journeys that avoided Pakistan airspace.

Singapore Airlines announced that some of its flights from Singapore to London would have to stop in either Dubai or Mumbai to refuel.

A map of flight paths in and out of Pakistan posted on Twitter by flight tracking company Flightradar24 on Wednesday showed all flights had stopped.

A number of Indian airlines announced the suspension of flights to several Indian airports on Wednesday, though services later resumed.

Aviation analyst Geoffrey Thomas said the route disruption was likely to cost airlines millions of dollars.

“It’s major corridor and this is a serious disruption as all traffic has been pushed much further south over the top of the Arabian gulf,” Thomas said. “You can’t go further north as you are then flying over the Himalayas – and you can’t do that. You’re locked into this corridor.”

Escalating border crisis

Tensions between India and Pakistan – which have been heating up since mid-February – spiked even further Wednesday when Pakistan claimed its air force shot down two Indian jets over the disputed border region of Kashmir.

The confrontation came a day after India said it launched airstrikes in Pakistan territory in the first such incursion by Indian air force planes since the India-Pakistan war of 1971.

India confirmed the loss of one plane in the Wednesday incident and said it shot down a Pakistani jet as it responded. Pakistan claimed to have captured an Indian pilot, with India demanding his safe return.

India and Pakistan both control parts of Kashmir, but each claims the region in full. The latest skirmishes are the most serious crisis over the disputed border area in years.

The immediate trigger for the latest confrontation was a suicide car bomb attack on February 14 in Indian-controlled Kashmir, which killed 40 Indian paramilitary soldiers. India blamed the militant group Jaish-e-Mohammed for the attack, the deadliest on security forces since the beginning of the insurgency in the late 1980s.

India also accused Pakistan of having a “direct hand” in the strike, which Pakistan denied.