DUBAI, United Arab Emirates (AP) — Major international airlines have canceled flights heading to the U.S. or changed the planes they’re using.

The moves Wednesday represented the latest complication in a dispute over concerns that 5G mobile phone service could interfere with aircraft technology.

Carriers took widely different approaches to the brewing crisis affecting international travel, from Emirates drastically reducing its U.S.-bound flights to Air France saying it would fly as normal.

It wasn’t immediately clear why the airlines made those decisions — or whether they took into account a pause in the rollout of the new high-speed wireless service near key airports.

But some said they received warnings from the U.S. Federal Aviation Administration or Boeing that the plane maker’s 777 was particularly affected.