They announced "a surprise attack on the enemy special operations command centre in the Al-Tanf region of Syria in revenge for the blood of martyred soldiers of Iranshahr", the IRNA state news agency said in a statement posted on Telegram.
Iran's Tasnim news agency reported on Sunday that funerals were held for three soldiers killed in a US attack on a barracks in Iranshahr, in the country's southeast.
On Friday, the Guards announced that they had attacked the Al-Tanf base, which the Syrian army took control of in February after the United States withdrew.
A Syrian military source later denied to AFP that any attack had taken place.
The Al-Tanf base is located near Syria's southeastern borders with Jordan and Iraq.
