A key airline route between Europe and Asia re-opened on Tuesday, almost five months after Pakistan shut its airspace in the wake of military escalations with India.

Pakistan closed its entire airspace in February after the Indian Air Force said it struck what it described as a terror camp—an allegation Pakistan denies—inside the boundaries of its western neighbor. Pakistan then shot down an Indian MiG-21 aircraft and captured a pilot.

While parts of the airspace had since reopened, global airlines were still forced to cancel or re-route flights to India from the West, and those to Southeast Asia from Europe. Carriers had to spend more than $200 million in extra fuel due to the closure, according to estimates by Instalocate, an artificial intelligence-based travel assist company. The disruptions caused $370 million in additional costs for as many as 1.8 million travelers to and from New Delhi, the company said.

The closure flew “in the face of the countries’ global responsibilities to civil aviation,” Peter Harbison, chairman emeritus at the CAPA-center for aviation, said before the ban was lifted. Airlines increased their fares to compensate, which may have offset or even outweighed the additional costs, he said.

Pakistan’s “unilateral measure” cost state-run Air India Ltd. $71 million until June 2, Indian aviation minister Hardeep Singh Puri told parliament this month. SpiceJet Ltd. and market leader IndiGo, operated by InterGlobe Aviation Ltd., lost $4.5 million and $3.6 million respectively, he said.

Pakistani airspace is the primary route between Southeast Asia and Europe, with about 220 services connecting the regions daily, according to the International Air Transport Association. Carriers from Singapore Airlines Ltd. to Qantas Airways Ltd. and United Airlines Holdings Inc. had to re-route their flights due to the ban.