WANA, Pakistan (Reuters) - Six kidnapped Pakistani workers for a Polish oil and gas company have been freed, a local official said on Monday, more than six months after they were abducted by a faction of the Taliban.

The six workers for oil and gas surveyor Geofizyka Krakow were recovered on Sunday night and have been moved to the main city in Pakistan’s northwestern South Waziristan region, according to Muhammad Tahir, the city’s political administrator.

The exact circumstances of the workers’ recovery were still unclear on Monday. The Polish Embassy referred all queries to the foreign ministry in Warsaw.

The Pakistani workers were snatched from their vehicles in November, 80 kilometers from the northwestern city of Dera Ismail Khan.

In 2008, a Polish engineer working for the firm was kidnapped by the Pakistani Taliban near the northwestern city of Attock and beheaded several months later.

In May, the same Pakistani Taliban faction released a video of the workers pleading for their lives and a spokesman, Azam Tariq, said the six would not be released until the militants’ unspecified demands were met.

Geofizyka Krakow, which has been in liquidation since August, could not immediately be reached for comment on Monday. In May, its parent company, PGNiG, said every effort was being made to find the workers.

Security in Pakistan has improved over the last few years but many of the northwestern areas bordering Afghanistan remain volatile and dangerous, especially for foreigners and those working with foreign companies.

The semi-autonomous northwest frontier region, hard to access due to rough terrain, has long been the sanctuary of fighters from al Qaeda, the Taliban and other militant groups.