The British government Tuesday called up an additional 1,200 soldiers to perform security duties at the Olympic Park in London, DPA reported.
The extra troops had already been on standby.
"With three days to go to the Olympics, we are not leaving anything to chance," said Jeremy Hunt, the minister responsible for the Games.
He said the call-up did not mean that the security situation had "deteriorated."
On the contrary, private contractor G4S - which had previously failed to provide enough staff - had lately been supplying more manpower.
The number of troops at the Olympic Park has now risen to 18,200 - out of a total security of 40,000.