Iran said on Friday it has launched an investigation into the death of a member of its Revolutionary Guards and denied reports that he had been assassinated.

"A member of the Revolutionary Guards died in recent days in an accident in his home," the official news agency IRNA said, citing what it called an informed source. 

It rejected "allegations" by foreign-based opposition media that Colonel Ali Esmailzadeh, a commander of the Guards' external operations unit, the Quds Force, had been killed in recent days in Karaj, west of Tehran.

The denial comes days after the Islamic Revolutionary Guard Corps accused Israel of shooting dead Colonel Sayyad Khodai on May 22.

Iran on Monday vowed to avenge the death of Khodai, 50, who was gunned down by assailants on motorcycles outside his home in the east of the Iranian capital.

It was the most high-profile killing inside Iran since the November 2020 murder of top nuclear scientist Mohsen Fakhrizadeh -- an act the Islamic republic also blamed on its arch enemy Israel.

IRNA said an investigation had been opened into the latest death, without giving further details.

The Guards are designated as a terrorist group by the United States.