A picture obtained by AFP from Iranian State TV IRIB shows smoke billowing from a tanker.

Iranian Foreign Minister Mohammad Javad Zarif said two oil tanker incidents in the Gulf of Oman on Thursday were "suspicious" and called for regional dialogue to avoid tensions.

Zarif tweeted that "reported attacks on Japan-related" oil tankers in the Gulf of Oman had taken place while Japanese Prime Minister Shinzo Abe was meeting Iran's Supreme Leader Ayatollah Khamenei "for extensive and friendly talks".

"Suspicious doesn't begin to describe what likely transpired this morning," he tweeted. "Iran's proposed Regional Dialogue Forum is imperative."