An attack on Iran's consulate in Najaf showed signs of being organised and was not carried out by Iraqi demonstrators, Iranian government spokesman Ali Rabiei said.
"According to our information, the attack on the consulate was not perpetrated by the Iraqi people, it was an organized attack," Rabiei said, as cited by the government information website.
On Tuesday, media reported that anti-government protesters in Najaf set the Iranian consulate on fire for the third time. The consulate was first torched on 28 November and then again on 1 December.
Talks have been continuing in Iraq over a new prime minister after weeks of protests in the country. People took to the streets in early October to protest against corruption, high unemployment and low living standards.