A very brief Xinhua news report was posted on CRIEnglish.com:
An explosion occurred at a restaurant in downtown Beijing Friday morning, witnesses said.
A local resident surnamed Sun said he heard the explosion. Another surnamed Qiao said the restaurant at Xinjiekou collapsed after the explosion, burying some people in the debris.
AFP has a few more details:
A policewoman in the Xinjiekou area of the Chinese capital told AFP that the initial investigation indicated the blast was accidental. She said she did not yet know whether anyone had been injured.
Above photos are from twitpic.com, the site is already being blocked by the Great Firewall.
The restaurant is located here. The updated Xinhua report has said it was gas cylinder explosion.