Police in north-west Pakistan say they have foiled a bid to abduct six officials working for the Pakistan Atomic Energy Commission (PAEC).
Police say the gang seized the staff south of Peshawar late on Sunday, but were stopped at a security checkpoint.
Three would-be kidnappers were shot dead in the gunfight, while two others were arrested. Police say they have yet to establish a motive.
PAEC set up an office in the area after high-grade uranium was discovered.
Series of raids
According to local sources, at least 20 armed men raided the PAEC office in the village of Banda Daud Shah in Karak district on Sunday night.
The kidnappers took the officials there hostage and set off with them towards the Orakzai agency in the nearby tribal areas.
However, they were stopped at the checkpoint after exchanging gunfire with security forces. All the hostages were freed.
According to the police, the kidnappers were from one of the tribal regions bordering Afghanistan.
They said those involved had been identified, but refused to give further details.
It is the latest in a series of incidents targeting governmental and non-governmental organisations in the area.
In recent months, dozens of vehicles and more than 50 people have been hijacked or kidnapped by criminal gangs, BBC correspondents say.
Police blame most of the incidents on criminals, although they say tribesmen have also disguised themselves as Taleban fighters to carry out the raids.
In addition, some of the stolen vehicles have been used in bombings, the authorities say.
Most of the raiding tribesmen are said to come from the Taleban stronghold of North Waziristan.