A blast that shook central Cairo on Friday morning took place near police headquarters, state television reported.
Reuters witnesses heard gunfire after the explosion. State television quoted witnesses as saying gunmen opened fire on buildings after the blast. Smoke was rising over the city centre.
Daily Telegraph journalist Magdy Samaan tweeted this picture:
More photo from the bombing http://t.co/tQ294fq7dl
Radio Sawa correspondent Zaid Benjamin shared this image: