ESCONDIDO —— Five human bones found in a field in unincorporated Escondido are believed to be those of an unidentified man, a sheriff's homicide investigator said Tuesday.

It isn't known yet how he died, Detective Jeff Maxin said.

A construction crew grading a field for a major housing development in the 2500 block of Royal Drive discovered the bones about 1:45 p.m. Friday, authorities said.

Maxin said clothing was also found, so investigators determined that the remains had been there for some time but not long enough to be part of an ancient burial site.

The case has been referred to the San Diego County medical examiner's office for further investigation. A medical examiner's investigator said a forensic anthropologist examined the bones Saturday.

Once the person's estimated height, weight, race and other information is available, missing-person reports will be examined for a possible match, she said.