BERLIN, April 12 (Reuters) - German flagship airline

Lufthansa has extended its suspension of flights to

and from Tehran by five days until April 18, the dpa news agency

reported on Friday citing a company spokesperson.

Lufthansa wasn't immediately available for comment.

The carrier first announced it had cancelled a flight from

Frankfurt to Tehran last weekend to avoid the crew having to

disembark and spend the night.

Middle East countries and the United States have been on

alert for a retaliatory attack by Iran since April 1, when

Israeli warplanes were suspected of bombing the Iranian embassy

compound in Syria.

Lufthansa and its subsidiary Austrian Airlines are the

only two Western carriers flying into Tehran, which is mostly

served by Turkish and Middle Eastern airlines.

(Writing by Friederike Heine, Editing by Miranda Murray and

Andrey Sychev)