NAIROBI, April 17 (Xinhua) -- Tanzanian athlete Alphonce Simbu, who pitched camp in Eldoret to train for the London Marathon, has picked up a hamstring injury forcing him out of the race on Sunday.

Simbu joins Kenya's Stanley Biwott who also pulled out of the race having picked up an injury in training.

Simbu ran a personal best of 2:9:10 to finish fifth in last year's elite men's race behind Kenyan winner Daniel Wanjiru.

Simbu almost ended the 36-year Olympic medal drought for his country when he finished fifth in the marathon at the Rio Games.

Simbu was one of 14 men in this year's line-up who have run the 42km distance quicker than two hours and ten minutes and he leaves a formidable field containing four men who have run a sub-2:04 and eight who have finished the race under two hours and six minutes.

Wanjiru will defend his title against three of the greatest distance runnersin the world.

Olympic champion Eliud Kipchoge is going for his third London Marathon victory after wins in 2015 and 2016. He is up against Ethiopia's Kenenisa Bekele, seeking a first London win after placing third and second in the last two years.

Finally everyone will have to pay close attention to Britain's Sir Mo Farah, kicking off his marathon career after winning multiple world and Olympic titles on the track.