(CNN) -- China's first aircraft carrier sailed out of the northeastern port of Dalian for sea trials Wednesday morning, the state-run news agency Xinhua reported. China has spent nearly a decade refurbishing the 67,000-ton, 300-meter (1,000-foot) ship, begun by the former Soviet Union but never completed. Xinhua quoted military sources as saying the trials would be brief, and the carrier would return to Dalian for further refits. China once renounced aircraft carriers as tools of imperialism, but has been developing a blue-water navy in recent years, along with air power to back it up. China's military modernization a cause for concern? It purchased the rusting, gutted shell of the Varyag, the Soviet-begun carrier now under way, from Ukraine in 1998. Only a handful of other nations operate aircraft carriers -- and only the United States, with 11, has more than two in service.
China has been refurbishing its still-unnamed carrier for years . The ship was begun by the Soviet Union but never completed .