LONDON (AP) — Britain put an extra 3,500 military personnel on standby Wednesday to protect venues at the London Olympics, after a private contractor acknowledged it may not be able to provide enough guards on time.

The contractor, G4S, had been enlisted to provide the bulk of the 13,200 private security guards across 100 venues, but said in a statement that it may not hit its target due to problems supplying staff.

The company has insisted that it still hopes to be able to supply the guards, but Britain's government is putting the troops on alert to be quickly deployed if the contractor cannot meet its obligations.