LONDON (AP) — British troops assigned on short notice to guard the Olympics are "enjoying a very unusual and memorable operation," London's mayor says.

But some soldiers have complained of less-than-ideal accommodations and others say they have not been able to get tickets to watch Olympic events.

Thousands of troops were deployed at short notice after private security firm G4S admitted it would not be able to provide the number of staff it had promised. Some have seen their leave canceled for Olympics duty.

On Friday, London Mayor Boris Johnson visited Tobacco Dock, a warehouse complex where 2,000 soldiers, sailors and air force personnel are sleeping on camp beds and using portable toilets.

The mayor said he had come to "thank them and congratulate them and listen to what they have got to say."

"I think there will always be some people who are positive and some people who are less positive, but the reaction I'm getting is that they are enjoying a very unusual and memorable operation, something they will keep with them for the rest of their lives," Johnson said.

As well as performing security duties, soldiers have been used to fill empty VIP seats left in stadiums.

Cornet Harry Thomas of the Household Cavalry said since his men were on standby as backups, they had not been given any Olympic tickets.

He said "the ticketing thing is a real shame."

"I understand the difficulty but I think potentially there is some scope for excess tickets, particularly if there are spare seats around the stadiums," Thomas said.