Employees at the park saw the victim, a man in his late 20s or early 30s, lying on the ground near the bathrooms on the park's ewa side at about 6:15 a.m, but they assumed he was a sleeping homeless man, said homicide Lt. Bill Kato.

When he hadn't moved after a few hours, employees called Emergency Medical Service crews, who declared the man dead at about 9:30 a.m., Kato said.

"EMS noticed blood on his face, probably caused by a blunt instrument," he said. "We're still calling it a suspicious unattended death, but it may be reclassified as a homicide after an autopsy."

Police interviewed homeless people who frequent the park, Kato added; they were unable to identify him and said the victim had been seen in the area only recently.

Witnesses told police that they had heard loud fighting at the opposite end of the park at about 3 a.m., but Kato said this may be unrelated to the victim's injuries. Although there were some signs the body had been dragged, he said, what appears to be blood was found on a picnic table near the body, indicating that an assault may have occurred there.

The medical examiner's office is expected to determine a cause of death today or tomorrow, he said.