PRESS ASSOCIATION -- Jamie Oliver's Birmingham restaurant has been hit by rioters as violence spread to the city.
Jamie's Italian, a 270-seat restaurant, was targeted in the world-famous Bullring shopping centre.
He tweeted: "So sad to see what's happening in UK with these riots! All gone mad. time to get our country back. Now we need to come down hard on these idiots."
He added later: "Sadly my restaurant in Birmingham got smashed up, windows all gone, whole area closed, can't open, staff and customers all safe!! thankfully."
Other celebrities tweeted about the voluntary clean up effort.
Simon Pegg tweeted: "Apparently the riotcleanup site is down, likely due to an excess of traffic which is both frustrating and extremely heartening."
X Factor presenter Dermot O'Leary said: "Out and about this morning. Already seeing strangers being more considerate/friendly to each other. Makes me proud."
The show's new judge, N-Dubz singer Tulisa Contostavlos, wrote: "Absolutely disgusting what's happening, as much as everyone deserves answers from the police, destroying our city is not going to get one. Feel so disappointed in humans right now, didn't realise there were so many evil people on this planet, god bless the innocent ones x."
Lily Allen wrote: "Are we on the brink of civil war or something? Bring back the cane ??????".
In the US, former Spice Girl Mel B wrote: "I am really worried for everyone in the UK right now, these riots must be stopped!!"