Three ships struck in Hormuz flare-up

Two tankers were hit in the Strait of Hormuz on Tuesday, including an LNG carrier at risk of explosion, as huge crowds mourning Iran's slain Supreme Leader Ayatollah Ali Khamenei thronged Qom.

Qatar blamed Iran for the attack on a huge Qatari liquefied natural gas tanker, the Al Rekayyat, which reported being struck overnight by a drone that caused a fire in its engine room.

The crew were safe and being evacuated, but maritime security sources briefed on the incident told Reuters the fire on board could put the ship at risk of blowing up.

A Saudi-flagged crude oil tanker, believed to be the supertanker Wedyan, was also damaged off Oman's coast, maritime security sources said. The cause was not immediately clear.

"Mayday mayday mayday. This is vessel Al Rekayyat, LNG vessel Al Rekayyat. We are being hit by drone on port side, top of engine room," the Qatari tanker's captain said in a recorded radio call reviewed by Reuters. "Status: engine room fire and full of smoke. Unable to assess further damage."

Qatari foreign ministry spokesperson Majed Al Ansari called the incident an unacceptable attack on the security of international navigation and global energy supplies, and a clear violation of international law.

He called on Iran to immediately halt actions threatening regional security and maritime navigation, and said Tehran bore full legal responsibility for the attack and any resulting damage or consequences.

There was no immediate comment from Tehran, or any claim of responsibility. A U.S. official, speaking on condition of anonymity, said initial indications were that Iran had fired at two commercial vessels.

In another incident later on Tuesday, a tanker was struck by a drone while transiting the strait, sustaining minor damage, but was able to sail to its next port of call, British navy-affiliated agency UKMTO said in a report.

The incidents were the first reported attacks in the strait since mourning for Khamenei began last week, highlighting the ongoing insecurity for Gulf shipping more than four months after the United States and Israel launched a war they said would stop Iran threatening its neighbours.

Iran's clerical rulers have exerted newfound control over the world's most important energy shipping route, where they aim to install a permanent system to collect fees in what would amount to a huge shift of the balance of power in a region where Washington has long acted as guarantor of security.

At home, the leadership has used the mourning period to show its control after Khamenei was killed with his daughter, granddaughter, son-in-law and daughter-in-law on the war's first day.

The caskets of the slain leader and family were driven through the streets of the seminary city of Qom on Tuesday.