Iranian President Hassan Rohani has blamed the United States and its regional allies for a suicide bombing in southeastern Iran that killed 27 members of the country's Islamic Revolutionary Guards Corps (IRGC).
"The crime will remain as a 'dirty stain' in the black record of the main supporters of terrorism in the White House, Tel Aviv, and their regional agents," Rohani said on February 14, a day after one of the deadliest attacks on Iranian security forces in years.
The IRGC says a suicide bomber on February 13 drove an explosives-laden vehicle into a bus that was transporting IRGC troops in Sistan-Baluchistan Province.
A militant Sunni Muslim separatist group called Jaish al-Adl (Army of Justice) claimed responsibility for the attack.
That group says it is seeking greater rights and better living conditions for Iran's ethnic Baluch minority.
Sistan-Baluchistan is a volatile area near Iran's borders with Pakistan and Afghanistan where militant groups and drug smugglers frequently operate.
The province is populated mainly by Sunni Muslim ethnic Baluchs.
Tehran has repeatedly accused the United States, Israel, and U.S. ally Saudi Arabia of backing Sunni militia groups that carry out attacks against Iranian security forces. They have denied the charges.
Rohani called on Iran's neighbors to assume their "legal responsibilities" and prevent "terrorists" from using their territory to prepare attacks.
"If this continues and they cannot stop the terrorists, it is clear -- based on international law -- that we have certain rights and will act upon them in due time," the Iranian president said, without elaborating.
Rohani made the remarks at Tehran's Mehrabad Airport as he was leaving for talks on Syria with Russian President Vladimir Putin and Turkish President Recep Tayyip Erdogan in Russia's Black Sea resort city of Sochi.
Iranian state television reported on February 14 that Supreme Leader Ayatollah Ali Khamenei was ordering immediate action against those responsible for the attack.
"There is a link between this crime...and some regional and international spying and intelligence agencies," Khamenei was quoted as saying.
Pakistani Foreign Ministry spokesman Mohammad Faisal said Pakistanis were "shocked and grieved" by the attack.