TOKYO/DUBAI (REUTERS, AFP) - Two "flying objects" damaged a Japanese tanker in a suspected attack on Thursday (June 13) in the Gulf of Oman, but there was no damage to the cargo of methanol, the president of the shipping company said on Friday.

The Kokuka Courageous was sailing towards the port of Khor Fakkan in the United Arab Emirates after the crew, which had evacuated after the incident, returned, president Yutaka Katada of Kokuka Sangyo told a press conference. It was being escorted by the US Navy, he said.

"The crew told us something came flying at the ship, and they found a hole," Mr Katada said. "Then some crew witnessed the second shot."

Mr Katada said there was no possibility that the ship, carrying 25,000 tonnes of methanol, was hit by a torpedo.

The crew saw an Iranian military ship in the vicinity on Thursday night, Japan time, Mr Katada said.

The United States blamed Iran for attacking the Kokuka Courageous and another tanker, the Norwegian-owned Front Altair, on Thursday, but Teheran denied the allegations.

Iranian Foreign Minister Mohammad Javad Zarif said in a Twitter post on Friday that the US administration had "immediately jumped to make allegations against Iran without a shred of factual or circumstantial evidence". He accused it of seeking to "sabotage diplomacy" amid a visit to Iran by Japanese Prime Minister Shinzo Abe and "cover up its economic terrorism against Iran" in enforcing crippling unilateral sanctions.

Japanese Industry Minister Hiroshige Seko said on Friday that the incidents will be discussed at a meeting of Group of 20 energy and environment ministers this weekend.

Mr Seko declined to comment on American officials blaming Iran, saying Japan is still investigating the incident, which occurred while Mr Abe was in Teheran trying to help ease rising tensions between the US and Iran.