Iranian media is reporting that ships in the Gulf of Oman have issued distress calls to port authorities in Oman and Pakistan.
The Maritime Trade Operations centre in the UK said it was aware of an incident but did not elaborate further.
It put the ships' position midway between Oman and Iran.
This comes a month after four tankers were attacked in the Gulf, not far from the UAE port of Fujairah.
Two were Saudi tankers, the others from the UAE and Norway.
Two tankers were evacuated in the Gulf of Oman after the incident but crew was safe, four shipping and trade sources said.
Marwan Kabalan, head of policy analysis at the Arab Center for Research and Policy Studies discusses the latest developments.