A homemade bomb has gone off in the Iranian city of Zahedan, in the southeastern Sistan and Baluchestan province, but a second explosive device apparently intended to cause massive casualties has been diffused by security forces.

The explosive device, revealed to be a homemade sound bomb, went off at around 2:30 am local time and prompted authorities to evacuate the area, according to a statement issued by Iranian police on Saturday.

Bomb disposal units present at the site identified a second bomb shortly after the initial explosion, diffusing the device after cutting a remote control link meant to activate the explosion.

The terrorist attack, yet to be claimed by any terror group, left no casualties but shattered windows of several shops in the vicinity.

Speaking later on Saturday, Sistan and Baluchistan provincial police chief Brigadier General Mohammad Qanbari said the second bomb, placed in a residential area, was made of a pressure-cooker pot filled with TNT and metal shrapnel.

Had the second explosion occurred, the attack could have led to many casualties, according to Qanbari.

The brigadier-general added that the police had obtained a number of clues indicating the perpetrators' identity and that they would be soon detained.

Qanbari also said that these types of operations, designed to target civilians, seek to project a negative image of the province.

"Therefore we expect people, especially the elders and tribal leaders of the province, to take a stance against such provocations," he added.

A similar sound bomb explosion injured two police officers responding to a set-up distress call last month. On Saturday, Qanbari said two individuals had been detained in connection with the attack.

Sistan and Baluchestan – which borders Pakistan -- has witnessed several terror attacks targeting both civilians and security forces over the past years.

Earlier this year, a suicide car bomb killed 27 people and wounded 13 others. The so-called Jaish ul-Adl terrorist group claimed responsibility for the bombing. The suicide bomber, along with a number of his accomplices, was later identified to have been Pakistani nationals.

Terrorist groups carrying out similar attacks against Iranian interests in southeastern and southwestern parts of the country have known links to Saudi Arabia and a number of other repressive regimes in the Persian Gulf region.

Riyadh is widely believed to be a key sponsor of Takfiri terrorists, who are inspired by Wahhabism, an extremist ideology preached by Saudi clerics. The extremist ideology promoted by Riyadh has put Saudi Arabia and Iran on the opposing sides of various conflicts across the Middle East.

Saudi Crown Prince Mohammed bin Salman, who is mired in an ongoing five-year conflict against its southern neighbor Yemen, has pledged to "take the war into Iran".