Police say they found an unidentified man's remains while searching a wooded area in Roosevelt Friday, where they've been searching since receiving a tip earlier this week.

Lilian Oliva-Santos, whose 19-year-old son Kerin Pineda went missing last year, says she fears the remains may belong to her son, although police say it's too early to identify the body.

Pineda went missing in May 2016, a week after he got in an altercation with MS-13 members over his sneakers, Oliva-Santos says. Pineda is among four young Hispanic men missing from nearby neighborhoods.

The 27-acre search site near Milburn Creek Pond off the Southern State Parkway contains rugged terrain and overgrown vegetation.

As News 12 has reported, local, federal and state officials, along with cadaver dogs, have been scouring the woods near West Greenwich Avenue for about two days. A so-called person of interest tipped off federal investigators with Homeland Security Investigations Wednesday. HSI is the investigative arm of Immigration and Customs Enforcement.

During a news conference on the discovery Friday afternoon, officials said they also identified two other potential "grave sites" that they also intend to search.

Detective Lt. Stephen Fitzpatrick, of the Nassau County Police Department, said the remains would undergo DNA testing.

"We don't know who this person is right now, so we don't know anything about his past or who he was associated with," he said.

Searchers found the body buried under a slab of concrete, according to authorities.

HSI has been probing the MS-13 gang, which police say is responsible for a number of slayings in wooded areas of Central Islip and Massapequa. Police did not immediately link the discovered remains to gang activity.