An historic run for Qatar's first female Olympic track athlete, Noor Al-Malki, was ended by injury.
BBC athletics commentator
“Poor Noor after being given the opportunity to come here and represent her country in such a historic moment”
The 17-year-old failed to finish her 100m heat after appearing to pull a hamstring as she came out of the blocks at London's Olympic stadium.
Al-Malki, dressed in a maroon running suit and cap, limped off the track with the help of officials after bursting into tears.
Al-Malki is one of four females who are competing for Qatar in London.
BBC athletics commentator Steve Cram, commentating on Al-Malki's heat, said: "It's a tragic situation for her. Poor Noor after being given the opportunity to come here and represent her country in such a historic moment, and it's such a sad way to end."
Al-Malki, with a personal best time of 12.73 secs, was not expected to qualify from her preliminary heat -
won by Congo's Lorene Bazolo in 11.87
- but her appearance was regarded as historically important.
It is the first time Qatar have sent female competitors to the Olympic Games.
Qatar's 12-strong Olympic team have already won a medal at the Games, shooter
Nasser Al-Attiyah taking bronze in the men's skeet event.