Iran's foreign minister has labeled the reported attack on two "Japan-related" oil tankers in the Gulf of Oman as "suspicious," occurring just as Japanese Prime Minister Abe came to Tehran for major talks.

Expressing his misgivings on Twitter, Javad Zarif noted that the incidents on the two vessels on Thursday, one of which had been reportedly struck by a torpedo, had occurred as Abe sat down for "extensive and friendly" discussions with Iran's supreme leader, Ayatollah Seyed Ali Khamenei.

Later in the day, Japanese shipping company Kokuka Sangyo confirmed that one of its vessels had been hit in today's attack while transporting 25,000 tons of methanol.

The statement came after Iran said it rescued 44 sailors from two tankers named as Front Altair and Kokuka Courageous. One of them was reportedly hit with a torpedo, but there is no official statement on the claim.