A polio worker, his driver and four tribal police guards were abducted on Monday after administering polio drops in Awaran town, 700 kilometres west of Quetta, the capital of oil and gas rich Balochistan province bordering Iran and Afghanistan.
The kidnapping was the latest setback to efforts to eradicate the disease in Pakistan -- one of only three countries in the world where the crippling virus is still endemic, along with Afghanistan and Nigeria.
"The vaccination team members, who had been snatched on gunpoint by over a dozen armed men Monday evening, returned to Awaran town Wednesday morning," senior local police official Rafiq Lasi told AFP.
No group has claimed responsibility for the kidnapping but militant groups see vaccination campaigns as a cover for espionage, and there are also long-running rumours about polio drops causing infertility.
More than 40 people, including health workers and police guarding the teams which administer polio drops to children, have been killed in Pakistan since December 2012.
Masked gunmen kidnapped another six-member polio vaccination team southwest of Peshawar in northwest Pakistan earlier this month. Their whereabouts are currently unknown.
Pakistan's failure to defeat polio stands in stark contrast to its neighbour and great rival India, which recently celebrated the eradication of polio three years after its last case.
Balochistan, one of Pakistan's most unstable provinces, is rife with separatist and Islamist militants and is plagued by sectarian bloodshed.
