The Iranian Revolutionary Guards Corps (IRGC) fired at least two missiles at commercial ships transiting the Strait of Hormuz overnight Monday, Axios reported, citing a US official.
The official told the news website that two commercial ships were hit and suffered significant damage, but that no casualties were reported.
Earlier, the United Kingdom Maritime Trade Operations (UKMTO) reported that an "unknown projectile" hit and caused a fire on an oil tanker off the coast of Oman near the Strait of Hormuz.
Tensions have been high in the region, even as the US and Iran continue their engagement in an attempt to reach a permanent deal after signing a Memorandum of Understanding.
Despite the talks, the US twice recently struck Iranian targets in the Strait of Hormuz in response to Iranian violations of the ceasefire.
President Donald Trump subsequently warned that the US may be forced to “militarily complete the job" if Iran continued to violate the ceasefire.
The Strait of Hormuz waterway normally facilitates the transit of roughly 20% of global liquefied natural gas and crude oil supplies. However, traffic ground to a near-total halt during the broader Middle East war due to an Iranian blockade, triggering a sharp spike in worldwide energy costs.
Tehran subsequently reopened the Strait of Hormuz following the initial preliminary accord with the United States to suspend active fighting.