President Yang, who has been secretary general of the party's Central Military Commission since 1981, has used his post to build a family empire.

Mr. Yang is the younger brother of President Yang, and that may explain his rise.

"At least sit at the rostrum to show unity," President Yang reportedly pleads.

Then President Yang makes an impromptu announcement ordering troops into the capital.

The front pages also included prominent photos of Mr. Deng and President Yang, suggesting who the real decision makers are.

The authorities gave few details, and there was no way of confirming the diagnosis or of verifying President Yang's condition.

The official said Mr. Yang is a nephew of President Yang, not a brother as has sometimes been reported.

Some analysts said President Yang was installed in his post by senior conservatives as a watchdog because of his relative good health despite his age.

President Yang is thought to be skeptical of the economic changes instituted over the last decade by Mr. Deng.

The 27th Army, while also in the Beijing Military Region, is linked to President Yang.