POLICE IN LOS Angeles have been left red-faced after a stash of powerful weapons were stolen from a building used by the area’s crack SWAT team.

The elite SWAT unit were due to train at a facility in the city last Thursday, but when they arrived they found that firearms left there for them overnight had been taken, the LA Times reports.

Among the weapons stolen were 15 MP-5 submachine guns and 15 Colt 45 handguns, which had been left in a locked box in the building overnight in readiness for the training session. Reuters reports that the building had no cameras or alarms.

“Unfortunately stuff’s going to get lost once in a while. This is a particularly bad one,” LAPD commander Andy Smith said. “It is embarrassing.”

However, officers stressed that the weapons had been altered to fire plastic training rounds instead of live bullets, and would require specialist engineering to render them dangerous.

“Right now these weapons are inert. They don’t fire bullets,” Smith said. “It takes significant skill and significant parts to reconvert these back.”

- Additional reporting from AP