China may have started work on it first domestically built aircraft carrier and is likely to produce a number of carriers over the next decade as part of an aggressive effort to modernize its military, AP quoted the U.S. Defense Department as saying Friday. In its annual report to Congress appraising China's military strength, the Pentagon also cited concern about China's targeting of U.S. and other foreign computer networks as a means of collecting strategic intelligence. It based this conclusion on unspecified "authoritative writings" and China's "persistent cyber intrusions." More broadly, the report described an ambitious Chinese military program aimed at transforming the People's Liberation Army into a modern force, fueled by years of double-digit increases in defense spending. Beyond that, China has been developing a capability to project power well beyond its shores, David Helvey, the acting deputy assistant secretary of defense for East Asia, told a Pentagon news conference. One element of that is its expansion of naval power, including an anti-ship ballistic missile seen as a potential threat to U.S. aircraft carriers. Last year China also launched sea trials of its first carrier, a refurbished hulk purchased from Ukraine. Friday's report said China also may have begun work on its first built-from-scratch carrier. The report, which in past years has drawn critical reviews in Beijing, was shorter than earlier versions and struck a measured tone. The Pentagon said it was meant to present data in a "descriptive, analytical manner." China's military buildup is a central focus of the Obama administration as it shifts its attention more toward Asia and the Pacific in the aftermath of fighting wars in the greater Middle East over the past decade. The U.S. is not building new permanent bases in Asia but is seeking more security partnerships in the region.