Joseph Wei Chan, air force liaison officer, and Dwayne Howard Florenzie, his assistant, appeared to be in good health, said a spokesman for the US Consulate-General in Hong Kong, where both men are based. They arrived from Xiamen, in China's south-east Fujian province, where they were detained on 29 July.
For the Chinese government, the timing of the expulsion could not have been better. All the main Chinese newspapers carried front-page stories yesterday alleging that the two officers' activities "seriously undermined China's national security". On Wednesday, the Chinese foreign ministry spokesman, Shen Guofang, said the two men entered China on 23 July and "sneaked into a number of restricted military zones in China's south-east coastal areas and illegally acquired military intelligence by photographing and video- taping". They were caught "on the spot", he added.
US officials said the two men were on "authorised travel", but have not explicitly denied the charges. Their arrival in China coincided with the People's Liberation Army's surface-to-surface missile tests from south- east China into the sea north of Taiwan.
Asked about the impact on Sino-US relations, the White House press secretary, Mike McCurry, said: "I'm not aware of any information that will lead me to assume there are going to be negative repercussions."
China held the men for five days, apparently so that the expulsions would not take place before last Tuesday's meeting in Brunei between the US Secretary of State, Warren Christopher, and his Chinese counterpart, Qian Qichen.
The case of the air force officers were not raised by either side at the meeting.