June 28 (Reuters) - Gulf stock markets closed mixed on Sunday as escalating military confrontations between the United States and Iran rattled investor confidence.

Iran launched missile and drone attacks on US military bases in Kuwait and Bahrain early today following US President Donald Trump's threat that he would destroy the country's leaders if they violated the interim peace agreement.

These attacks represent the culmination of a week that saw escalating violence in the Middle East, threatening to undermine the fragile peace agreement. Just one day after a new ceasefire was agreed upon, Israel bombed targets belonging to the Iranian-backed Lebanese group Hezbollah, while the United States launched new airstrikes against Iran following an Iranian attack on an oil tanker in the Strait of Hormuz.

The Saudi index fell 0.2 percent, affected by a 1.2 percent drop in shares of the National Bank of Saudi Arabia and a 3 percent decline in shares of ACWA Power.

However, shares of Saudi oil giant Aramco rose 1.8 percent, ending an eight-session losing streak.

The Saudi Press Agency (SPA) reported that an Aramco helicopter crashed today in Ras Tanura on the eastern coast of Saudi Arabia, killing 14 Saudis, adding that the cause of the accident is unknown.

In Qatar, the index rose 0.1 percent, supported by a 0.7 percent increase in shares of Qatar National Bank.

The Kuwaiti index fell 0.1 percent, while the Bahraini index rose 0.3 percent and the Omani index jumped 1.2 percent.

Outside the Gulf region, Egypt's blue-chip index fell 2.1 percent, with most of its listed stocks declining, including Commercial International Bank, which dropped 2 percent.

The Cabinet announced today that Egypt has granted "temporary registration to four companies within the government offerings program".