FILE - In this Friday, June 14, 2019 file photo, Yutaka Katada, president of Kokuka Sangyo Co., the Japanese company operating one of two oil tankers attacked near the Strait of Hormuz, shows a photo of the attacked oil tanker during a news conference in Tokyo, Japan. A series of attacks on oil tankers near the Persian Gulf has ratcheted up tensions between the U.S. and Iran -- and raised fears over the safety of one of Asia’s most vital energy trade routes, where about a fifth of the world’s oil passes through its narrowest at the Strait of Hormuz. (AP Photo/Jae C. Hong, File)

DUBAI, United Arab Emirates (AP) — A series of attacks on oil tankers near the Persian Gulf has ratcheted up tensions between the U.S. and Iran — and raised fears over the safety of one of Asia’s most vital energy trade routes, where about a fifth of the world’s oil passes through its narrowest at the Strait of Hormuz.

The attacks have jolted the shipping industry, with some of the 2,000 companies operating ships in the region on high alert and ordering their vessels to transit the Strait of Hormuz only during the daylight hours and at high speed.

Washington’s accusation that Iran is behind the attacks targeting oil tankers comes as tensions flare between the two countries. The U.S. has deployed an airstrike carrier and bombers to the region, and announced this week it will send 1,000 more troops.

European powers are facing a deadline from Tehran to ease the effects of punishing U.S. sanctions — described by its leaders as “economic warfare” — or Iran will break out of the limits set on its uranium enrichment by the landmark 2015 nuclear deal.

The apparent targeting of tankers is alarming to ship owners operating in the Persian Gulf, said chief shipping analyst at BIMCO, Peter Sand.

The company dubs itself the world’s largest shipping association.

But it’s more or less business as usual for shippers, he said, despite the need for added precautions.

“They are all of course increasingly worried, but many of them are going with business as they would have done without the attacks, but of course with an extra layer of safety and security measures on top of that,” Sand said.

That means going at high speed through the Strait of Hormuz, which at its narrowest point is about 2 miles wide. Normally, vessels carrying cargo would slow down to save on fuel costs.

It also means avoiding the strait at night to keep better watch on security around the vessel.

Washington alleges Iranian forces surreptitiously planted limpet mines on two vessels in the Gulf of Oman last week. The attack forced the evacuation of all 44 crewmembers onboard and left one of the ships ablaze at sea.

Washington also blamed Iran for similar attacks on May 12 that targeted four oil tankers anchored off the coast of the United Arab Emirates. Iran denies being involved.

The attacks last week targeted the Norwegian-owned MT Front Altair, which had a cargo of highly flammable naphtha loaded from the UAE, and the Kokuka Courageous, a Japanese tanker carrying Saudi methanol. Both had been traveling through the Gulf of Oman, having passed the Strait of Hormuz.

Of the roughly 2,000 companies that operate ships in the Persian Gulf, only two companies have halted bookings outright. Otherwise, “business has continued more or less undisrupted,” Sand said.

In fact, higher risks could boost the bottom line for some oil shippers, after a lackluster period for the industry. A risk analysis by shipping services company Braemar ACM said owners can ask for higher premiums now. The firm said the Gulf region was declared as a “Listed Area”, meaning it faces enhanced risk, after the May 12 incidents targeting tankers off the UAE coast.

Immediately after last week’s attacks, freight rates for operators in the Gulf rose 10-20%.

With increased risks, however, come higher insurance premiums, which are expected to rise 10-15%.

It’s typically the buyers and charterers who bear the brunt of the overall higher costs, another reason why security of the Strait of Hormuz is paramount for oil-importers around the world. An estimated 18-20 million barrels of oil — much of it crude — pass through the strait every day. BIMCO says anywhere between 10-40 vessels carrying just crude oil move through daily..”