March 3 (Reuters) - Gold prices rose for a fifth straight session on Tuesday as investors flocked to safe-haven assets amid escalating U.S. and Israeli air warfare against Iran, raising fears the conflict could turn into a protracted regional war and exacerbating uncertainty.

Gold rose 1 percent in spot trading to $5,377.21 an ounce by 0122 GMT. In the previous session, gold prices climbed to their highest level in more than four weeks after the United States and Israel launched strikes on Iran over the weekend.

U.S. gold futures for April delivery rose 1.5 percent to $5,391.90.

Tim Waterer, senior market analyst at KCM Trade, said, "The scope and duration of the conflict remain uncertain, and with this uncertainty, gold is capturing the largest share of safe-haven demand."

Iranian media quoted a senior Revolutionary Guard official on Monday as saying that the Strait of Hormuz had been closed, warning that his country would fire on any ship attempting to pass through the strategic waterway.

This is Tehran's most explicit warning since it notified ships on Saturday that it would close the strait, a move that threatens to halt a fifth of global oil flows and sharply raise crude prices.

The dollar hovered near its highest level in more than five weeks, which it reached on Monday, supported by strong demand and caution in the market.

A stronger dollar typically makes dollar-denominated assets like gold more expensive for holders of other currencies, but this inverse relationship is not absolute. In times of heightened uncertainty, such as escalating conflicts or broader market volatility, investors often buy both dollars and gold as safe-haven assets.

Waterer added, "Gold could have been trading at higher levels than it is now if it weren't for the dollar's rise since the conflict intensified. Inflation concerns are currently on traders' minds, given the direction of oil prices and the decline in shipping volumes through the Strait of Hormuz."

The attack on Iran led to a war in the Gulf, killing dozens of civilians in Iran, Israel and Lebanon, plunging global air transport into chaos and halting navigation through the Strait of Hormuz.

As for other precious metals, silver rose 1.4 percent in spot trading to $90.67 an ounce on Tuesday, after climbing to its highest level in more than four weeks in the previous session.

Platinum rose 0.6 percent to $2,316.50 in spot trading, while palladium climbed 1.6 percent to $1,795.08.