The Islamic Revolutionary Guard Corps (IRGC) has denied that its ships were involved in any type of confrontation with British ships in the Persian Gulf on July 11. The public relations office of the IRGC navy said its forces were conducting their normal routines and “in the last 24 hours have not encountered any foreign boats.” Had the IRGC navy intended to seize a British boat, the statement read, its forces would do so “without delay, with firmness and with speed.”

According to British authorities, Iranian boats attempted to impede a British oil tanker in the Persian Gulf but were driven off by the HMS Montrose. The British Ministry of Defense said the Iranian boats attempted to bring the BP-owned tanker to a halt as it was attempting to exit the Persian Gulf near the island of Abu Musa and pass through the Strait of Hormuz.

Iran’s Foreign Minister Mohammad Javad Zarif dismissed the British claims about the incident. “They put forward a claim to increase tensions, and this claim has no value and they have presented these claims many times,” Zarif said to reporters when asked about it.

Tensions have increased between Iran and the UK after an Iranian oil tanker was seized by the UK off the coast of Gibraltar last week. The tanker was carrying 2 million barrels of crude to Syria. Iran has demanded that the vessel be returned, arguing that it is not subject to EU sanctions on exporting oil to the Syrian government.