MIDEAST STOCKS-Gulf markets slump on escalation in Israel-Iran conflict

June 15 (Reuters) - Stock markets in the Gulf tumbled in early trade on Sunday as conflict escalated between Israel and Iran, sparking fears of broader Middle East conflict.

Israel and Iran launched fresh attacks on each other overnight into Sunday.

Israel said it had targeted Iran's nuclear facilities, ballistic missile factories and military commanders on Friday at the start of what it warned would be a prolonged operation to prevent Tehran from building an atomic weapon. Iran has promised a harsh response.

Tehran has called off nuclear talks that the United States had said were the only way to halt Israel's bombing.

The Qatari stock market index .QSI slid 4%, with all constituents in negative territory. Among them was Qatar National Bank QNBK.QA, the Gulf's biggest lender, which retreated 3.3%.

Saudi Arabia's benchmark index .TASI plunged 3.6% as stocks fell across sectors, while the Kuwait bourse .BKP lost 3% and the Bahrain index .BAX eased by 0.8%.

Elsewhere, Muscat Stock Exchange .MSX30 registered a 1.9% fall.