ABOARD LIAONING AIRCRAFT CARRIER, Jan. 3 (Xinhua) -- A naval formation consisting of aircraft carrier Liaoning has conducted take-off and landing drills in the South China Sea on Monday, a military source said on Tuesday.

The fighter "Flying Shark" ready for takeoff on the deck of China's first aircraft carrier, the Liaoning, during a training mission in the South China Sea on January 2, 2017. The carrier took part in a multi-tasking training exercise involving the Jian-15 aircraft and on board helicopters. [Photo: chinanews.com]

The formation, which is on a "cross-sea area" training exercise, involved J-15 fighter jets, as well as several ship-borne helicopters, the source said without giving specific numbers.

Complex hydrological and meteorological conditions in the South China Sea as well as a cold front in area have posed some challenges, but the source said the drill provided important experience in the build-up of combat capability of the aircraft carrier formation.

The "Flying Shark" jet fighter takes off from the deck on a signal given by a crew member. Refueling in the sky and air-defense confrontation were also part of the training exercise. [Photo: chinanews.com]

The formation led by the first Chinese aircraft carriers, the Liaoning, in the South China Sea for a training mission on January 2, 2017. [Photo: chinanews.com]

An aerial view of the Liaoning, China's first aircraft carrier, in the South China Sea during a training mission on January 2, 2017.