SAN DIEGO -- Investigators looking into the abduction of 7-year-old Danielle van Dam extended their search to Mexico Thursday, 10News reported.

MISSING Danielle van Dam 4 feet tall, 58 pounds Blue eyes, dirty blond hair Possibly wearing blue pajamas Watch Danielle Video Montage INFORMATION Danielle Recovery Center: (858) 485-4185 Tips: (619) 531-2000 Danielle Missing Flyer DISCUSSION Share your feelings, thoughts for van Dam family

"Detectives were in Mexico today following up on one of the 500+ tips we have received," wrote David Cohen, of the San Diego Police Department, in an e-mail to reporters. "There is no word that she has been found."

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Brenda van Dam Encouraged By Mexico Search

Cohen also answered recent Internet speculation about extending the search to the Coronado area. David Westerfield, 50, a suspect in Danielle's disappearance had spent an evening at Silver Strand State Park before heading to the desert on the weekend that Danielle was first discovered missing.

"Members of the (SDPD) horse patrol and from the Chula Vista Police Department's mounted reserve unit were on the Silver Strand today, searching for any sign of Danielle. Nothing of significance was located," Cohen wrote.

Closer to the van Dam family's northern San Diego home, more than 30 Marines from Marine Corps Air Station Miramar looked for clues to the missing girl's disappearance in the brushy foothills off Highway 67 in the vicinity of Poway and Lakeside.

Organizers at the Poway-based Danielle Recovery Center are also planning a third weekend of searches in the desert, one in Borego Springs and one in Shelter Valley.

Meanwhile, a candlelight vigil in honor of the missing 7-year-old was held at St. Timothy's Episcopal Church in Rancho Penasquitos Thursday night.

Friday evening, concerned citizens will join San Diego Police Department officials at a "town hall" meeting featuring a talk by Marc Klaas of Petaluma, whose own young daughter was abducted and murdered in 1993. That gathering will take place at Creekside Elementary, where Danielle attended second grade.

As they have regularly done over the last three weeks, Danielle's parents repeatedly met with the press in front of their upscale home this week, again urging the public to keep looking for the child.

Damon van Dam told reporters Wednesday that his family's ordeal "could happen to anyone."

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Marines Join In The Search

"We were just like everyone else out there watching this now," he said. "We were the exact same people you are. ...This is an awful, awful thing, and just everyone else needs to know that this can happen to you."

"I think everyone takes it for granted, their security," added his wife, Brenda. "I mean, you're in your home, you're in a safe neighborhood -- you feel safe."

When the van Dams reported the girl missing the morning of Feb. 2, they told authorities that the last they had seen of her was when her father put her to bed after 10 p.m. the night before.

The parents are not suspects in the girl's disappearance, which is officially considered a case of abduction, authorities have said.

This week, SDPD crime lab workers returned to the van Dams' home to do some follow-up evidentiary work at the scene of her presumed kidnapping.

They removed closet doors from Danielle's upstairs room Wednesday "to continue processing (tasks) that we began several days ago," Cohen told reporters.

"We will not discuss why those doors might be important to the case," he said.

Police have collected more than 100 pieces of what they call "potential evidence" from the family's Mountain Pass Road house, from Westerfield's home two doors away, and from two vehicles he owns.

Investigators have focused much of their efforts on Westerfield, who took a desert trip around the time Danielle disappeared.

Though the design engineer has come under close and near-constant law enforcement scrutiny, authorities have not taken him into custody and continue to refer to him only as a "potential suspect" in the case.

Investigators have searched his home and impounded his sport utility vehicle and motor home, and he has provided a DNA sample for analysis.

Police officials also disclosed this week that they are delving into previous area child-abduction cases to look for links to Danielle's disappearance.

In addition to looking through the sun-baked wastelands of neighboring Imperial County, teams of community volunteers have gone over considerable open territory in eastern San Diego-area communities in recent days.