BEIJING (AFP) - Usain Bolt said he might end his glittering career at next year's Olympics after he completed a world sprint double in Beijing - and got clattered by an electric scooter into the bargain.

The towering Jamaican said he was only 50-50 about running at the next world championships in 2017 in London, and could retire at the Rio de Janeiro Olympics instead.

"After Rio, as I said, my sponsors want me to go one more year, but my coach said, 'Listen to me, if you're not going to be serious about going to the world championships in London, then I shouldn't do it," he said.

"So it's all about how I feel after Rio, if I feel I can really put my body through one more season. If I'm going to be focused and I'm going to be determined.

"That will determine if I compete after Rio. So we'll see how it goes."

Bolt, troubled by pelvic problems this year, was pushed all the way by Justin Gatlin in Sunday's 100m. He had an easier ride in the 200m as he beat the American by nearly two-tenths of a second.

However, Bolt's celebrations came to a sticky end at the Bird's Nest stadium on Thursday when a TV cameraman riding an electric scooter lost control and ploughed into him from behind, sending the Jamaican flying.

"I probably should get my legs insured," said the six-time Olympic champion with a smile. "It was pretty scary when it happened but accidents happen."

Some Chinese Internet users commented that the cameraman was the only person who was able to take down Bolt in Beijing.