"In this suicide attack a auto filled with explosives blew up beside a bus carrying a unit of the Guard ground forces causing the martyrdom and wounding of a number of the protectors of our Islamic homeland's border", it said.
Jaish al-Adl group claimed responsibility for the roadside bomb attack, which came on the day of a US-led conference in Warsaw that included discussions on what America describes as Iran's malign influence across the wider Mideast. In 2009, more than 40 people, including six Guard commanders, were killed in a suicide attack by extremists in Sistan and Baluchistan province.
"Foreign-backed terrorists kill & wound innocents in Chabahar".
Earlier this month, Jaish al-Adl was blamed for an attack on a paramilitary base in Nik Shahr that left one Revolutionary Guard dead and five others wounded.
Jaish al-Adl emerged as the main armed opposition movement in the southeast after members of another Sunni group, Jundullah, joined it after their leader was captured on a plane in 2010.
Iranian officials have blamed Saudi Arabia and the United States for stirring up dissent in the country.
The bombing comes on the day of a US -led conference in Warsaw, Poland that included discussions of what the United States described as Iran' "malign influence" across the wider Middle East.
Neighbouring Pakistan condemned the suicide attack, "Shocked and grieved to hear about the suicide attack on IRGC bus near Zahidan today, in which many lives were lost", Foreign Office spokesperson Dr Mohammad Faisal said in a statement. President Donald Trump, who campaigned on a promise of tearing up Tehran's nuclear deal with world powers, withdrew the USA from the accord last May.
"Especially when cohorts of same terrorists cheer it from Warsaw streets & support it with twitter bots?"
Iranian border guards have repeatedly come under attacks by terror outfits active on the Pakistani soil.