(Adds Pakistan foreign ministry comment)
ANKARA, April 4 (Reuters) - Four Iranian border guards have been freed in Pakistan two months after being seized by al Qaeda-linked militants on the countries' lawless frontier, Iran's semi-official Fars news agency reported on Friday.
Fars quoted Iranian lawmaker Esmail Kosari announcing the news. It did not give any details of when the release took place or what brought it about.
The abduction in early February heightened regional and sectarian tensions. Iran had said the guards were taken into Pakistan and it threatened to send troops over the border to retrieve them.
The kidnapping was claimed by Jaish al-Adl (Army of Justice), a Sunni Muslim rebel group operating in predominantly Shi'ite Muslim Iran's Sistan-Baluchistan province, which borders Pakistan. The movement said it had killed a fifth member of the group of guards in March.
"Four of the five abducted Iranian border guards have been handed over to Iranian embassy officials in Pakistan," Fars quoted Kosari as saying.
Iran's Students News agency ISNA quoted a statement from Jaish al-Adl saying "Sunni clerics' mediation led to the guards' release ... as a sign of our goodwill".
Fars also said the body of a slain guard had been handed over to officials of Tehran's embassy in Pakistan.
The Pakistani government had repeatedly said there was no evidence the Iranian guards were on its territory. The Iranian government accused its neighbour of not doing enough to free the men and of supporting the rebels.
Pakistan authorities could not confirm the release of the abducted guards.
"They have not been released in Pakistan. We don't know where they were kept or releasedwe have no indication that these Iranian border guards were kept in Pakistan," Pakistan Foreign Ministry spokeswoman Tasnim Aslam told Reuters.
Iranian media in October reported killing of 14 Iranian border guards by the same group near the border town of Saravan.
The border region is also rife with drug and arms traffickers. (Additional reporting by Katharine Houreld in Islamabad; Writing by Parisa Hafezi; Editing by Tom Heneghan)