There may have been bruises but there were no hard feelings after London Mayor Boris Johnson knocked over a 10-year-old Japanese boy during a game of rugby.

Sports fan Johnson plowed into Toki Sekiguchi Thursday while thundering down a turf-covered street rugby pitch in Tokyo.

After they both got up, Johnson asked whether the boy was OK before shaking his hand and saying "I'm so sorry."

Later the pair posed for photographs and Johnson gave Sekiguchi a rugby ball.

The boy said that he "felt a little bit of pain," but it had been "enjoyable" meeting the mayor.

Johnson, who is on a trade visit to Japan, said later that he felt "terrible" about the collision.

Last year Johnson knocked over a 9-year-old during a soccer match.