On Saturday, a plane full of vacationers disappeared from radar and crashed in a mountainous region in the Sinai Peninsula, killing all 224 passengers and crew aboard. Now, Germany’s transport ministry is warning airlines against flying the same route above Egypt’s Sinai Peninsula, stoking rumors about the cause of the crash.

So far, Lufthansa, Emirates and Air France have announced they will no longer fly over the region until the cause of the crash has been found. Other airlines continue to fly in the region.

CNN reports that the plane broke up while still in mid-air, but that the cause of the crash wasn’t yet determined. A spokesperson for Russia’s Interstate Aviation Committee told reporters:

“Disintegration of the fuselage took place in the air, and the fragments are scattered around a large area (about 20 square kilometers).”

The pilot didn’t send distress calls before the crash, said Egyptian Civil Aviation Minister Hossam Kamel at a press conference.

“There was nothing abnormal before the plane crash,” he said. “It suddenly disappeared from the radar.”

Kogalymavia Flight 9268, which reportedly had 25 children aboard, was headed for St. Petersburg in Russia. A national day of mourning was declared in Russia after the crash.

[Image via Getty]