Burbank police say broken glass has been found buried in the sand under two slides at Johnny Carson Park twice so far this month.
The glass was reported by park-goers on Sept. 2 and 16, according to police.
No injuries were reported, and police said it was not yet known if the glass pieces were intentionally buried, although the cases remain under investigation.
In a public safety notice issued today, Burbank police urged parents to walk through the playground and inspect equipment areas before allowing their children to play.
Anyone with information on the glass investigation may call police at (818) 238-3000.