LOS ANGELES (Reuters) - Los Angeles police officials searched on Monday for a stolen cache of submachine guns and semi-automatic handguns that disappeared from a SWAT training facility, and said they were embarrassed by the loss.

More than 30 Heckler & Koch MP5 submachine guns and M1911 pistols that had been stored at the training facility were stolen, Los Angeles Police Department spokeswoman Karen Rayner said.

The weapons had been altered to fire blanks, and it would be “difficult” -- although not impossible -- to convert them back to full use, she said.

“If somebody knew what they were doing, it would be rather labor intensive but it is possible to get them fully functional again,” Rayner said.

The guns were discovered missing last week after they were kept overnight in a warehouse without cameras or alarms on the SWAT training grounds, Rayner said. She said there have so far been no arrests in the case or leads in the recovery effort.

Police were considering the possibility of the theft being an inside job, Commander Andrew Smith told a news conference to announce the thefts.

“It’s embarrassing,” Smith said. “Once in a while we’ll have a police car get stolen. That’s certainly embarrassing, and any time we lose any of our property it’s embarrassing and we want to get it back.”