The Iranian authorities on Saturday hanged 16 "rebels" following overnight clashes in which 14 border guards were killed on the frontier with Pakistan, a judicial official said.
"Sixteen rebels linked to groups hostile to the regime were hanged this morning in the prison of Zahedan in response to the death of border guards in Saravan," Mohammad Marzieh, the attorney general of Sistan-Baluchestan province, was quoted as saying by Fars news agency.
"We warned the rebel groups that any attack targeting civilians or members of the security forces would not go unanswered," he added.
The official IRNA news agency, quoting what it called an informed source, said the clashes in which the border guards were killed occurred in a mountainous region used by both drug traffickers and armed rebels.
Deputy Interior Minister Ali Abdollahi said that the guards had been killed during the ambush set by Iranians who were "members of hostile groups".
He added that "three soldiers have been taken hostage and taken to the other side of the border in Pakistan".
The Sistan-Baluchestan province, home to a Sunni Muslim majority, has seen militants from the Sunni group Jundallah (Soldiers of God) launch bloody attacks in recent years.
In October 2012, a suicide attack against a Shia mosque in the far south of the province killed at least two people and wounded several others.