China's first aircraft carrier completes sea trials

China's first aircraft carrier that raised global concerns returned to its base after completing a four-day maiden voyage to test its system and capabilities.

The carrier, refitted from an imported platform called Varyag from Ukraine, was towed back to the Dalian port in northeast China's Liaoning Province by tugboats after four days of tests in the Yellow Sea, official Xinhua news agency said.

During the trials the carrier's engines, electronic systems, navigations and weapons were checked.

The report said all its weapons systems were concealed from public view. China reportedly plans to build two more such carriers.

The first sea trials were in line with the schedule of the carrier's refitting project work would continue, it quoted officials as saying.

The carrier is expected to officially start service with the Chinese Navy in August next year and an official naming ceremony for the vessel would be held next October.

It said the carrier might also have tested the taking-off and landing of aircraft, though China yet to reveal what type of aircraft it plans to use on its first carrier.

Yin Zhuo, a Chinese military expert, claimed the carrier's radar system was among the most advanced in the world.

The Chinese-made system, known as the "Chinese Aegis" to compare with the Aegis Combat System initially used by the United States Navy, can cope with supersonic missiles as efficiently as the US system, he said.

The radar system has been used on two of the Chinese Navy's destroyers.

Li Jie, a researcher of the China Navy Military Academy, said some unmanned aerial vehicles might have landed on the carrier.

The carrier is capable of hosting 30 Chinese-made J-15 fighters and helicopters and will have a crew of around 2,000.

The vessel was originally built by the former Soviet Union, which failed to complete construction before its collapse in 1991. Ukraine disarmed the carrier and removed the engines before selling it to China.

The US sought explanation from China regarding the need for such kind of war equipment and asked it to be more transparent about its power projections.

"We have had concerns for some time, and we've been quite open about them with regard to the lack of transparency from China regarding its power projection and its lack of access and denial of capabilities," State Department spokesperson, Victoria Nuland had said in Washington.

"We want to see more transparency. We would welcome any kind of explanation that China would like to give for needing this kind of equipment. As you know, President Obama and President Hu have stated together that they want a healthy and reliable military-to- military relationship," she had said.