bus carrying members of Iran's elite paramilitary force has been targeted in a
suicide bombing in the country's southeast, leaving at least 20 people dead and
20 more wounded.
Twenty seven members of Iran's IRGC had been killed in the suicide attack in southeast Iran on Wednesday .
The attack 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 Middle East.
Jaish al-Adl (Army of Justice), a Sunni militant group seeking greater rights and better living conditions for the ethnic minority Baluchis, has claimed responsibility for the attack.
The heavy losses among Iran's premier military force prompted a senior Revolutionary Guards commander to issue a warning to the country's foes.
"Our response in defense of the Iranian Revolution will not be limited to our borders," Ali Fadavi was quoted as saying.
"The enemies will receive a very firm response from the Revolutionary Guards like before." He did not specify which enemies or what actions Tehran would take.
Iran’s authorities say militant groups operate from safe havens in Pakistan and have repeatedly called on the neighboring country to crack down on them.
The incident took place in Iran's Sistan and Baluchistan province, which lies on a major opium trafficking route and has seen occasional clashes between Iranian forces and Baluch separatists, as well as drug traffickers.
The IRGC is a major economic and military power in Iran, answerable only to the country's supreme leader, Ayatollah Ali Khamenei.