The Russian leader made the comments in a message sent to his Iranian counterpart on Saturday, a few hours after four gunmen, disguised in the Islamic Revolution Guards Corps (IRGC) and Basij uniforms, opened fire on people from behind a viewing stand at Quds Boulevard in the city of Ahvaz during the parade held to mark the former Iraqi dictator Saddam Hussein's invasion of Iran in the 1980s.

Deputy Governor of Khuzestan Province Ali Hossein Hosseinzadeh told Iran's Mehr News Agency that the death toll had risen to 25 from an initial figure of 10. He added that at least 60 other people had sustained injury. A four-year-old boy was also among those who had received fatal wounds.

Three of the terrorists were shot dead at the scene while a fourth was arrested and later succumbed to his wounds, armed forces spokesman Brigadier General Abolfazl Shekarchi said.

“Please accept the deepest condolences regarding the tragic consequences of the raid by terrorists in Ahvaz. We are appalled by this bloody crime,” said Putin in his message, a copy of which was posted on the Kremlin website.

“We expect that everyone involved will face a deserved punishment. This event once again reminds us about the necessity of an uncompromising battle against terrorism in all of its manifestations. I would like to confirm our readiness to continue building cooperation with Iranian partners in resisting this evil,” the Russian leader added.

Putin also extended his heartfelt sympathy to the bereaved and wished speedy recovery to the wounded.

The Saudi-backed al-Ahvaziya terrorist group claimed responsibility for the attack. However, the British Broadcasting Corporation (BBC) only used the word "attack" for the act of terror.

Similarly, Reuters and others described the incident as an "attack" instead of a terrorist one, whereas they have been quick to use "terrorist attack" for similar incidents that have taken place in Europe over the past few years.

Meanwhile, the Takfiri Daesh terrorist group claimed responsibility for the attack but provided no evidence for the claim.

Syria denounces Ahvaz terror attack

In the wake of the bloodshed in the Iranian city, the Syrian Foreign Ministry issued a statement, vehemently condemning the act of terror and stressing that terrorists and those supporting them in the region would not be able to achieve their goals through such crimes.

An unnamed official source from the ministry further told Syria's official SANA news agency that Damascus had expressed its “full sympathy” to and “solidarity” with Iran, reaffirming that those behind “such sordid crimes” were doomed to fail.

The official also offered the Syrian government’s “warmest condolences” to the Iranian leadership, government and people as well as families of the victims, wishing quick recovery to the wounded.

Pakistan against any terrorism

In a statement issued by Pakistan’s Foreign Office, Islamabad also slammed the deadly terrorist attack and expressed solidarity with Tehran and the families of those killed and wounded in the brutal shooting.

Elsewhere in the statement, cited by the Daily Pakistan, the ministry said the Pakistani government was against any kind of terrorism.

Turkey slams “heinous” terror attack

The Turkish Foreign Ministry also “strongly condemned” the terrorist attack in a statement carried by the state-run Anadolu news agency.

“We wish Allah’s mercy upon those who lost their lives and a speedy recovery to the wounded. We convey our condolences to the people and Government of Iran,” the statement said.