'We send our deepest condolences to the people of Iran following the attack in Ahvaz this morning. Our thoughts are with the families of the victims and those injured,' UK Minister of State for the Middle East and International Development Alistair Burt said in a message released in his twitter account on Saturday.

Earlier, the UK envoy to Iran Rob Macaire in a message blasted the terrorist attack in southwestern city of Ahvaz.

'A shocking terrorist attack. Wherever it happens terrorism must be condemned. All our condolences to the families of the victims,' Macaire tweeted Saturday.

At least 25 people were killed and more than 60 others injured during Saturday morning terror attack in Ahvaz, capital of Khuzestan Province, in southwestern Iran.

“The terrorists disguised as the Islamic Revolution Guards Corps (IRGC) and Basiji (volunteer) forces opened fire at the authorities and people from behind the stand during the parade,' Governor of Khuzestan Gholam-Reza Shariati said earlier.

The self-proclaimed Saudi-affiliated Al-Ahwaz terrorist group claimed the responsibility for the attack.