MOUNTAIN LAKES — Tuesday will mark one week since 15-year-old Thomas Kolding went missing after an argument with his parents, and police are still hoping he can be found safely.

Detective John Hukowski of the Mountain Lakes Police Department said there have been a few possible sightings of the teen over the past six days, but nothing concrete to help them locate him. Police do not believe Kolding was abducted from his parents' house, and are investigating several leads to hopefully find him.

"They got into an argument about his grades on Monday, and on Tuesday night he left," Hukowski said.

Hukowski said Kolding has no history of running away, and police had not been called to the home for any issues in the past. Although Kolding may have left on his own, police are concerned that being out on his own could be dangerous because he is young and is relatively small in stature.

Aleksandra Wieleba Kolding via Facebook

"We're more worried about taking advantage of him," Hukowski said.

Kolding's mother, Aleksandra, has posted Facebook on about her son's disappearance since Friday night, calling him a "wonderful, resourceful, and far-too-adventurous young man who we are worried about beyond words."

On Sunday she updated her post to say that while there had been no update on his location people should be on the lookout for a boy with a "very LARGE BLACK BACKPACK." She said the bag could be the "telltale sign for those that don't recognize him."

Aleksandra Wieleba Kolding via Facebook

Police believe Kolding took a train from the Denville train station to Newark and then moved on to New York, where the trail went cold. Hukowski said police have images of the boy at the train station with the bag that "looks like he has his whole life in there."

"If somebody sees this kid travelling alone that should be a dead giveaway as well," he said of the bag. "This kid does not look like he belongs to be traveling by himself."

Thomas Kolding, child missing November 2018 from Morris County. (Morris County Prosecutor's Office)

Kolding's mother's post has been shared more than 42,000 times since it was put up on Friday. The number of shares has nearly doubled since Sunday alone.

Kolding is described as having brown hair, standing 5 feet 3 inches, and weighing 120 pounds. He was last seen wearing a camouflage jacket and a gray skull cap.

Anyone with information is asked to call the Mountain Lakes Police Department at 973-334-1413.