Iran has seized another foreign oil tanker in the Gulf, the country's state TV reported on Sunday, accusing it of smuggling fuel to Arab states and adding that seven sailors on board the tanker had been detained.

"The IRGC's naval forces have seized a foreign oil tanker in the Persian Gulf that was smuggling fuel for some Arab countries," TV quoted Revolutionary Guard commander Ramezan Zirahi as saying.

"It carried 700,000 liters of fuel. Seven sailors onboard of the tanker, who are from different nationalities, were detained."

NBC News has not verified the claim.

The report comes weeks after Iran seized a British oil tanker in the Strait of Hormuz, an incident that inflamed tensions amid renewed hostility between Iran and the West.

Tehran claimed that it had seized the Stena Impero for violating international regulations.

State TV later released video that shows masked commandos rappelling onto the ship, while a dramatic audio recording emerged of the moments before the tanker was seized.

A senior official in the government of Oman — which has often played a role as mediator in the region — told NBC News that Iran may have been reacting to the extended detention of one of its ships in the British territory of Gibraltar.

Last month British Royal Marines seized a tanker believed to be carrying Iranian oil in Gibraltar under accusations that it was bringing the oil to Syria in violation of E.U. sanctions.

Both ships remain in custody. Britain has rejected the idea that it could release the Iranian tanker in exchange for the British-flagged vessel seized by the IRGC.

Britain has called Iran's seizure of the Stena Impero a "hostile act" and rejected Tehran's claims that the vessel had been involved in an accident with a fishing boat.

Tensions between Iran and the United States have also intensified in recent months.

The Trump administration said Wednesday it has imposed financial sanctions on Foreign Minister Mohammad Javad Zarif, saying he carries out the country's "reckless agenda" and acts as an apologist for the regime.

The move, though largely symbolic, could complicate any attempt to open up direct talks between Washington and Tehran.

The designation underscored the lack of any dialogue between the two countries, despite increasingly hostile rhetoric and a series of tense standoffs in the Persian Gulf that have raised the possibility of a potential war.

Iranian officials announced last month that 17 people who were allegedly spies working for the CIA had been captured, with some sentenced to death. The U.S. government never acknowledges CIA recruitment abroad but President Donald Trump blasted the reported arrests on Twitter as "totally false."

Senior U.S. officials said earlier last month that U.S. Marines jammed an Iranian drone in the Gulf of Hormuz, bringing it down and destroying it.

A U.S. surveillance drone was earlier shot down by Iran's Revolutionary Guard. In the aftermath of the incident, Trump confirmed that he was "cocked and loaded" to strike Iranian targets but decided to call the strikes off, saying the loss of life would make it a disproportionate response.

U.S. officials also accused Tehran of a "blatant assault" on two burning tankers in the Gulf of Oman in June. Iranian officials denied any involvement in the attack on the tankers.

Iran and the United States have had no diplomatic relations for four decades but Zarif had been a key interlocutor for the previous administration in its diplomacy with Tehran.

Since Washington pulled out of the 2015 nuclear accord between Iran and world powers, Trump has imposed tough economic sanctions that have drastically slashed Iran's oil exports and helped fuel inflation.