A car bomb has exploded in south-west Moscow near a crowded McDonald's restaurant.

At least seven people have been injured, including a child, police said.

Suddenly there was a strong explosion. I was in shock. It was horrible

Sergei, eyewitness

Police have ruled out a terrorist motive and say it was probably connected to criminal activity.

Itar-Tass news agency, quoting Moscow police, said a bomb in a Lada car outside the restaurant had exploded at about 1300 local time (0900 GMT).

Police said the bomb was home-made and appeared to have been packed with metal filings.

The restaurant is a popular weekend destination for families and it was full of diners at the time.

"I drove up and then suddenly there was a strong explosion. I was in shock. It was horrible," said an eyewitness called Sergei.

Investigation under way

Itar-Tass reported that the victims were on the first and second floors of the restaurant and on the street near the car.

The vehicle had been parked by the exit of the drive-in section of the restaurant.

Investigators had to use McDonald's bags

Officials from Russia's Federal Security Service were at the scene sifting through the debris.

Witnesses said they were using takeaway bags from the restaurant to collect evidence.

The restaurant was badly damaged in the blast and several cars on the street had their windows blown out.

The car that held the bomb was totally destroyed.

Police said they had found the licence plate and were trying to trace the car's owner.