MIDEAST STOCKS-Gulf markets fall as fresh Houthi strikes on Saudi Arabia raise regional risk

Oct 22 (Reuters) - Major Gulf stock markets fell in early trade on Thursday as fresh attacks by Yemen's Iran-aligned Houthis on Saudi Arabia fueled fears of a broader regional escalation.

The US State Department has ordered some diplomats and family members to leave its missions in Saudi Arabia. It also plans to pull family members from several other US missions in the region, US officials told Reuters.

The order followed attacks in Saudi Arabia that killed two people and injured eight at a civilian airport in Dammam. A drone strike on an oil field killed two more.

Saudi Arabia's benchmark index .TASI fell 1.2% and was poised for its eighth weekly decline. Saudi National Bank 1180.SE, the country's biggest lender by assets, slid 1.9%, and oil giant Saudi Aramco 2222.SE lost 0.5%.

Riyadh has answered the Houthi attacks with a wave of strikes on missile launcher sites. It has vowed to protect the kingdom and said it has intercepted many of the group's ballistic missiles.

Dubai's main index .DFMGI dropped 0.8%. Top lender Emirates NBD ENBD.DU fell 2.4%, and utility firm Dubai Electricity and Water Authority DEWAA.DU fell 1.5%.

In Abu Dhabi, the index .FTFADGI lost 0.5%.

Tensions also rose in the northern Gulf. Iran's Islamic Revolutionary Guard Corps Navy said four vessels involved in illegal oil transfers were hit simultaneously and caught fire after its forces tracked them on Wednesday.

Meanwhile, Iranian media separately reported explosions of unknown nature and origin in Sirik, in southern Iran.

Qatar's index .QSI retreated 0.8%. Qatar National Bank QNBK.QA, the Gulf's biggest lender, lost 1.1%.