MOSCOW (Reuters) - Memo to Russian President Dmitry Medvedev: next time you plunge into a crowd, don't forget to park your car first.

Medvedev took his "Forward, Russia!" motto a bit too far in an incident captured on video, stepping from the driver's seat of an SUV and then frantically trying to hold the vehicle back as it kept moving toward a group of people waiting to greet him.

Burly bodyguards swiftly came to his aid and managed to stop the car, a big black Mercedes, before it bore down on the gasping crowd on Saturday in Kazan, a city 720 km (450 miles) east of Moscow.

"Oh, Dmitry Anatolyevich," a man is heard exclaiming in an admonishing tone in the video.

Nobody was reported hurt, but the gaffe drew some acerbic comments, driving tips and theories about what went wrong from a few of the 80,000 people who have watched the grainy clip posted on Youtube by user voronkov74.

"He left it in drive, the rookie," user ezikmarconi wrote.

"Instead of guns, his guards should be given bricks to throw under the wheels," user lqfvb80u wrote, adding a smiley face.

The Kremlin declined to comment on the incident, and it was unclear exactly what caused it. State media made no mention of the incident and the Youtube video was posted on Tuesday, three days after it occurred.

Auto accidents are a major cause of death and injury in Russia, where car ownership was a luxury 20 years ago but has exploded since the 1991 Soviet collapse, and driving licenses can often be bought for a bribe.

Medvedev and Prime Minister Vladimir Putin, who steered him into the presidency in 2008, appear to share the growing Russian affection for cars and have frequently taken the wheel in public appearances or when hosting foreign leaders.

The clip of the incident in Kazan was the second eyebrow-raising video this year depicting Medvedev, who is widely seen to be seeking Putin's support for a second presidential term in a March 2012 election.

A video posted in April showed Medvedev dancing to "American Boy," a 1990 pop hit whose lyrics about escaping with a foreigner struck a chord amid the economic hardship and uncertainty accompanying the collapse of the Soviet Union.

Putin, who has said he may run for president himself in 2012, has kept his private life closely under wraps.

(Reporting by Alexei Anishchuk; editing by Steve Gutterman and Paul Casciato)