Iran hanged 16 “rebels” from an unspecified armed group Saturday in retaliation for the death of 14 border guards in clashes near the frontier with Pakistan, a semiofficial news agency reported.

The executions took place hours after the rebels ambushed the border guards near the town of Saravan in southeastern Iran, the Fars agency quoted a local judicial official as saying.

State TV said that rebels had crossed the border from Pakistan and fled back across after the clash. Drug smugglers have occasionally ambushed Iranian troops in the mountainous area, which lies astride a major transit route linking Afghanistan to Europe and the Persian Gulf. Ethnic Baluchi armed groups also operate there but recently have been much less active.

The border in the remote region is porous, and groups can easily move back and forth.

The report provided few details of the hangings. It did not mention a trial, suggesting the prisoners may already have been convicted and sentenced to death and their executions were moved up after the ambush.

The state news agency IRNA had earlier described the attackers as “bandits.” It said authorities were investigating whether the attackers were drug smugglers or an armed opposition group.

Meanwhile, an Iranian official said authorities would probe claims by the daughter of detained opposition leader Mir Hossein Mousavi that she was bitten and hit by a female guard during an argument that broke out after she visited her parents.

IRNA quoted an unnamed security official as saying that the Intelligence Ministry, which supervises the detentions of Mousavi and his wife, will investigate any failures or fault by the guard. However, the official said Mousavi’s daughter was at fault in the incident, claiming that she insulted and attacked the guard.

The opposition Kaleme Web site on Friday recounted the allegations by Nargess Mousavi: that she was abused by the guard, who demanded that she and her sister consent to a strip search after visiting her parents, who have been under house arrest since early 2011.

Nargess Mousavi claims the guard struck her in the head and bit her on the wrist after she refused to be searched.

Her father and another opposition figure, Mehdi Karroubi, were placed under house arrest after leading protests over the disputed reelection of then-President Mahmoud Ahmadinejad in 2009.