The Great Britain 400m runner Martyn Rooney has been left stunned by the news that his friend and training partner Oscar Pistorius has been charged with murder.

Rooney was with Pistorius at a training camp in South Africa as recently as last week, and has been too upset to comment directly on the news that Pistorius's girlfriend, Reeva Steenkamp, was shot dead at the athlete's home in Pretoria on Thursday.

However, in a statement released through British Athletics, Rooney said: "My thoughts and prayers go out to the families and friends of those involved. I will not be making any further comment on the events of this week and ask that this decision is respected."

Pistorius's family and management have said in a statement that the 26-year-old denies the allegation of murder "in the strongest terms".

The Jamaican sprinter Shelly-Ann Fraser-Pryce, who retained her 100m title at the London Olympics, said she first heard the news when she arrived in Britain to take part in this weekend's Birmingham Grand Prix.

Fraser-Pryce said: "When I came off the plane at Heathrow and I gave the immigration officer my passport she said: 'What's your purpose for being here?' I said: 'I'm an athlete' … she said: 'Do you know Oscar Pistorius?' I said: 'Yes'. She said: 'He shot his girlfriend.' I was like: 'Are you serious?'

"I've not really drawn a conclusion yet. I've not really processed the information. I've not heard what he has to say so it's very difficult to actually comment."

The American sprinter Carmelita Jeter added: "I've seen him a couple of times at track meets, and he has always spoken to me and been very nice, so that's all that I know of him.

"I don't really know him as a person. It's definitely a sad situation, but the only thing I know is the same thing I saw on the news. I don't like to speculate. It will soon come out exactly what happened."