DUBAI, United Arab Emirates (AP) — A ship anchored off the United Arab Emirates was seized and taken toward Iran and another — a cargo ship near Oman — sank after being attacked, authorities said Thursday, as tensions escalated near the Strait of Hormuz.

It wasn't immediately clear who was behind these incidents, but they happened as a senior Iranian official reiterated his country's claim of control over the waterway and another said it had a right to seize oil tankers connected to the U.S.

READ MORE: Ship operators fear fuel shortages as Iran war squeezes supply

The turmoil in the strait, which a fifth of the world's oil passed through before the war, has been a sticking point for weeks in talks between the U.S. and Iran to end the conflict. Iran's grip on the vital waterway has jolted the world economy and spiked fuel prices far beyond the Middle East.

The ongoing instability in the region came as U.S. President Donald Trump met with Chinese leader Xi Jinping in Beijing. The White House said both sides had agreed that the Strait of Hormuz must remain open.