ANKARA, Turkey (AP) - Turkey’s navy and air force, which back the U.N.-supported government in Libya's capital, have conducted exercises in the Mediterranean Sea near Libya, officials said Friday, an apparent show of backing for Tripoli.


The Turkish military said the drill was meant to test and develop Turkey’s ability to command and execute long-distance operations. A Government official, speaking on customary condition of anonymity in line with government regulations, said the maneuvers took place in international waters and airspace off the coast of Libya.


The military said 17 warplanes, based in the central Turkish air base of Eskisehir, and eight frigates took part in Thursday’s “Open Sea Training.” The drill lasted for eight hours and took place along a 1,000 kilometer (625 mile) -route from the Turkish coast and back.


Turkey has backed the Tripoli forces in Libya against their rival, east-based Libyan fighters under the command of Khalifa Hifter, who launched an offensive in April last year to capture the capital.


With Turkey’s military support, the Tripoli-based forces have gained the upper hand after retaking the capital’s airport, all main entrance and exit points to the city and a string of key towns near Tripoli.


Libya has been in turmoil since 2011, when a civil war toppled long-time dictator Moammar Gadhafi, who was later killed.


Hifter is backed by the United Arab Emirates, Egypt and Russia, while the Tripoli-based militias are aided by Qatar, Italy and Turkey.


Separately, Turkey has also signed a maritime deal with the Tripoli-based government that would give Ankara access to an economic zone across the Mediterranean, despite the objections from Greece, Cyprus and Egypt. Turkey has said it will begin exploring for natural resources there within months.