While Trump has emphasized that his campaign did not collude with Russia, he has never condemned Russia since his inauguration and lawmakers are concerned.
Trump tweeted the FBI missed signals before a school shooting, and "are spending too much time trying to prove Russian collusion with the Trump campaign."
The ATR-72, a twin-engine turboprop used for short-distance regional flying, went down some 390 miles south of the capital, Tehran.
Israel launched attacks on 18 targets belonging to the Hamas militant group after four soldiers were wounded Saturday when a bomb detonated on the border with Gaza.
Doctors with the Syrian American Medical Society report a sharp rise in the number of hospital attacks since the start of the year.