Investigators were still combing the weeds in Howard Beach for evidence on Thursday after a Queens jogger was strangled to death there, as Chief of Detectives Robert Boyce pleaded with the public for leads in the case after raising the reward to $10,000.

Karina Vetrano, 30, was found dead just before 9 p.m. on Tuesday, about four hours after she had left her family home to go for a run.

“We will out there for several days,” Boyce said, speaking at police headquarters on Thursday. “We plan to chop down just about every weed in that location until we’re satisfied that we got all the evidence.”

Boyce said the forensic evidence that has been collected so far in what he called “an extraordinary case of murder” and has been taken to the medical examiner’s office. Boyce confirmed that Vetrano was sexually assaulted, and added, "This woman put up a ferocious fight right to the end."

Vetrano’s body was found facedown in a marshy area with her underwear pulled down, about 15 feet from a trail near 161st Avenue and 78th Street in Spring Creek Park. Her family began searching for her after growing concerned when she didn’t come home and didn’t answer any text messages or phone calls, police have said. Neighbors and police have said Vetrano sometimes jogged with her father, but had gone alone that night.

On Thursday, Boyce said Vetrano had texted her best friend after she had started her run.

“They were going back and forth,” he said, adding: “They were talking about something girls talk about, just what to wear and things of that nature.”

The phone has been swabbed for DNA, and if any is found it will be run through the Combined DNA Index System.

Boyce said police have spoken to people in her personal life, including an ex-boyfriend, who is not a suspect. Investigators have also reviewed surveillance video in the area, but “haven’t found any video evidence at all to show anybody lingering.”

But so far police have only received three CrimeStoppers tips, “and they’re all pretty generic,” Boyce said.

“This is a remote area,” he said, but added that it was “still daylight, so we’re hoping somebody saw something.”

Mayor Bill de Blasio said he hopes anyone with information -- “even the possibility something might help the police” -- should come forward.

“This is a real tragedy and, as a parent, my heart goes out to the father,” he said. “I can only imagine what he is feeling, and all of us have to help this family.”

Boyce said that “stranger rapes are down in this city” but said this type of incident “where you have a jogger in a park . . . in daylight hours is extraordinarily unusual.”