Libya's U.N.-backed Presidential Council has confirmed the release of three Turkish nationals after they spent 233 days in captivity in the southwestern town of Ubari.

In a statement on Sunday, the council said the three had left Ubari Airport and were en route to capital city Tripoli, from where they traveled back home to Turkey.

According to Turkish Prime Minister Binali Yıldırım, "They were freed in an intensive, precise and difficult process and they arrived home this morning and met with their families." The prime minister was speaking to reporters after casting his vote in the Turkish elections Sunday in the western province of Izmir.

Turkish prime ministerial sources previously said Osman Emre Yaykın, Tuğrul Can Kapubağlı, and Sertaç Karan, all working for the Turkish construction firm Enka, had been freed. The captives, who had been kidnapped in Ubari in November, were released from captivity after intense efforts in cooperation with Libyan authorities, said the sources.

Yıldırım reportedly conveyed the information to the employees' families over the phone.

Last November, an unknown armed group kidnapped four engineers, three from Turkey and one from South Africa. The engineers were working on a 640 MW power plant in Ubari deep in Libya's south, some about 950 kilometers (590 miles) away from of Tripoli. The fate of the South African is not known.

Kidnapping is rife in Libya, especially in the lawless south. Work at the Ubari plant has been going on for years and was in the final stages when the kidnapping happened. A week after the four engineers were kidnapped the firm evacuated 93 of its staff from Libya. Work on the power plant has stopped since that time, a blow to efforts to lure back foreign firms.

Most foreign companies have shied away from working in Libya because of security problems following the NATO-backed toppling of Moammar Gadhafi in 2011.

The country is now split between rival governments, each backed by an array of militias.