Gulf stock markets fell on Sunday as investors weighed growing geopolitical tension after the U.S. said Iran will suffer if it does not agree a deal on its nuclear activity in a matter of days.

U.S. President Donald Trump said on Thursday that "really bad things" would happen if Tehran does not come to an agreement to curtail its nuclear programme. Trump set a deadline of 10 to 15 days.

The Qatari benchmark index <.QSI> was down for a second straight day, falling 0.6%, with most constituents lower. Qatar National Bank <QNBK.QA>, the region's largest lender, ws down 1.4%, while Qatar Gas Transport <QGTS.QA> dropped 2%.

Outside the Gulf, Egypt’s blue-chip index <.EGX30> also fell for a second day, losing 2.2%, with nearly all its stocks declining. Commercial International Bank <COMI.CA> retreated 2.2%, while Fawry for Banking Technology <FWRY.CA> fell 5.3%.

SAUDI ARABIA

<.TASI> closed

KUWAIT

<.BKP> down 0.5% to 9,197

QATAR

<.QSI> lost 0.6% to 11,161

EGYPT

<.EGX30> fell 2.2% to 49,561

BAHRAIN

<.BAX> down 0.1% to 2,062

OMAN

<.MSX30> lost 0.1% to 7,217

(Reporting by Md Manzer Hussain)