New Delhi: Amid heightened tensions between Tehran and Washington over its nuclear deal, Iran’s Revolutionary Guard claimed on Thursday that it shot down a US "spy drone" which violated Iranian airspace near the Strait of Hormuz. The United States declined to immediately comment on the claims, news agencies reported.

The claim of the downing of the US RQ-4 Global Hawk comes after the US military previously alleged Iran fired a missile at another drone last week that responded to the attack on the two oil tankers near the Gulf of Oman.

The US had blamed Iran for the attack on the tankers, a claim that Tehran had denied.

Iran's paramilitary Revolutionary Guard, which answers only to Supreme Leader Ayatollah Ali Khamenei, said it shot down the drone on Thursday morning when it entered Iranian airspace near the Kouhmobarak district in southern Iran's Hormozgan province. Kouhmobarak is some 1,200 kilometers (750 miles) southeast of Tehran and is close to the Strait of Hormuz, the Associated Press reported.

Iran's state-run IRNA news agency, citing the paramilitary Revolutionary Guard, identified the drone as an RQ-4 Global Hawk.

Shooting down the drone on Thursday was "a clear message" that Iran will defend its borders, the head of the Revolutionary Guard said.

The tensions between US and Iran are on rise ever since Donald Trump decided to withdraw from Iran’s nuclear deal with world powers a year ago.

Iran has recently increased its production of low-enriched uranium and threatened to boost its enrichment closer to weapons-grade levels.