The American fast-food chain McDonald's has stationed security guards at all its outlets in Singapore after seven people were injured when a glass door shattered as crowds jostled to obtain promotional dolls offered with the hamburgers.

It's the second incident of its kind since the promotion was launched on New Year's Day ,when a doctor and a lorry driver had a fist-fight over the dolls.

McDonalds says it will limit the number of hamburgers which can be bought by each customer to try to prevent further incidents. The popularity of the dolls -- based on Japanese cartoon characters -- has made it difficult for producers to meet the demand.

From the newsroom of the BBC World Service