German airline Lufthansa said Friday its planes would no longer use Iranian airspace as it extended a suspension on flights to and from Tehran amid soaring Middle East tensions.
"Due to the current situation, Lufthansa is suspending its flights to and from Tehran up to and including Thursday, 18 April," a company spokesperson said Friday.
"The airline is also no longer using Iranian airspace."
Its subsidiary Austrian Airlines followed suit.
The flights to the Iranian capital have been suspended since April 6.
Lufthansa did not outline the immediate reasons for the suspension.
In a statement, Austrian Airlines cited "the current situation in the Middle East".
"For Austrian Airlines, the safety of its passengers and crews has top priority. The situation in the Middle East is being evaluated on an ongoing basis. To this end, Austrian is in close contact with the authorities".
The move comes after Iran blamed arch-foe Israel for a strike in Syria this month that killed two Iranian generals, and threatened reprisals.
Israel has stepped up strikes against Iran-linked targets in Syria since the war in the Gaza Strip began in October.