The WC-135 Constant Phoenix aircraft, which "sniffs" the atmosphere for signs of nuclear activity, was conducting a routine mission Wednesday in international airspace over the East China Sea when two Sukhoi Su-30 fighter aircraft intercepted it, the officials said. "The concerns about the recent activities of China along with the reclamation activities and construction of airstrips in the disputed territory is shared by other countries as it adds to the tension in the region," said Herminio Coloma, Philippine presidential communications secretary. The Philippines plans to install a $1 million satellite-based system on Thitu to track commercial flights over the South China Sea, after China landed its first test flights this month on a reef it built in the Spratly islands. China has been ramping up research into advanced new military equipment, including submarines, aircraft carriers and anti-satellite missiles, which has rattled nerves regionally and in Washington as China takes a more muscular approach to territorial disputes in places like the South China Sea.
Two Chinese aircraft intercept a US WC-135 aircraft over the East China Sea.