NEW DELHI (Reuters) – Several airlines, including Emirates and Qatar Airways, suspended flights to Pakistan on Wednesday after the South Asian nation closed its air space following heightened tensions with neighbouring India.

Etihad, flydubai, Gulf Air, SriLankan Airlines and Air Canada also suspended services to the country and flight tracking portals showed Singapore Airlines, British Airways and others were forced to reroute flights.

Airlines flying over India and Pakistan to Europe, the Middle East and Asia were disrupted and some flights were routed through Mumbai on India’s western coast, so they could head further south and avoid Pakistan air space, an Indian government official told Reuters.

Pakistan carried out air strikes and shot down two Indian military jets on Wednesday, Pakistani officials said, a day after Indian warplanes struck inside Pakistan for the first time since a war in 1971, prompting leading powers to urge both of the nuclear-armed countries to show restraint.

Tension has been elevated since a suicide car bombing by Pakistan-based militants in Indian-controlled Kashmir killed at least 40 Indian paramilitary police on Feb. 14, but the risk of conflict rose dramatically on Tuesday when India launched an air strike on what it said was a militant training base.

Mark Martin, founder and chief executive at Martin Consulting India, said about 800 flights a day use the India-Pakistan air corridor, making it “very critical”.

“You can’t overfly China, so you have to overfly Pakistan and India and go to Southeast Asia and Australia. Most of the traffic destined for Bangkok and Singapore will have to fly over Iran and then possibly take a detour,” he said.

International airlines that normally transit between Indian and Pakistani airspace have been forced to reroute, including flights by Singapore Airlines, Finnair, British Airways, Aeroflot, and Air India, according to online portal flightradar24.com which tracks the movement of planes globally.

Qatar Airways said in a statement it has temporarily suspended flights to eight cities in India and Pakistan “due to the ongoing situation on the India-Pakistan border” and that its flights routed over the India-Pakistan air space may be delayed due to rerouting in the area.

Bahrain’s Gulf Air said it had suspended all fights to and from Pakistan due to closure of airspace while low-cost carrier flydubai said it is reviewing its schedule. Emirates and Etihad also said they had suspended some flights to Pakistan.

All flights from Kabul to India have been cancelled until further notice while India’s state-run carrier Air India has cancelled its flights until the first week of March, an airline official in Kabul said.

Air Canada said it has temporarily suspended service to India because of Pakistan’s airspace closure.

Singapore Airlines’ Europe-bound flights would need to make refueling stops, the airline said in a statement. British Airways said it is monitoring the situation closely.

DOMESTIC DISRUPTION

India, earlier on Wednesday, shut several airports in the northern part of the country temporarily, leading to dozens of domestic flight cancellations after Pakistani warplanes crossed a disputed border into the Indian side of Kashmir.

Operations at the Indian airports have now resumed.

Indian airlines including IndiGo, India’s biggest airline by market share, low-cost rival GoAir and full-service carriers Jet Airways and Vistara, a joint venture between Singapore Airlines and Tata Sons, were forced to cancel services to at least six cities in northern India due to airport closures.

The airlines said on Twitter that flights to cities including Amritsar, Chandigarh, Dehradun, Jammu, Leh and Srinagar have been put on hold or temporarily suspended.

Airports in the cities of Amritsar, Pathankot, Jammu, Leh and Chandigarh were temporarily closed for commercial flights earlier on Wednesday, sources told Reuters.