Finding locked tables in SE

We have SE on HP-UX. Having a problem with people locking tables and forgetting to unlock them. They are scattered all over Minnesota, so tracking them down geographically is difficult. "wall" is too disruptive and often they have turned away from their workstations. Is there a way to query the system tables to determine which table is locked and who is locking it? Is there *any* way to determine which table is locked and who is locking it? Thanks.