The stepfather of two children who are missing in a rural area of Pictou County, N.S., said Sunday he wants authorities to monitor the New Brunswick border and nearby airports in case the children were abducted.

Lily Sullivan, 6, and Jack Sullivan, 4, were last seen Friday morning at their home on Gairloch Road in Lansdowne Station, about 20 kilometres southwest of New Glasgow.

Police maintain they are still actively searching for the children who they believe wandered off from their home. The RCMP say the search will continue overnight Sunday.

Daniel Martell has been in a relationship with the children’s mother for three years. (Josh Hoffman/CBC)

Daniel Martell has been in a relationship with the children’s mother for three years.

He said the last time he saw the children he and their mother were in their bedroom with their baby on Friday morning.

He said Lily came into the bedroom several times and he could hear Jack in the kitchen.

The children must have opened the sliding back door, which is almost silent, and left, he said.

“When we noticed that the children were gone, I immediately jumped in the vehicle, surveyed all the areas, [as] many dirt roads, [as] many culverts as I could and waited for the police to get there,” Martell said.

Jack was wearing a pull-up, he said, and Lily had a white backpack with red strawberries on it which should be highly visible.

Martell said he wishes the response by the authorities had been a lot faster and that more resources had been made available.

He is hoping that members of the public can help with the investigation. “If anybody out there has anything, come forward now,” he said.

RCMP Staff Sgt. Curtis MacKinnon said Sunday that 160 searchers were still doing their work despite challenging weather conditions.

MacKinnon said searchers located what could be a footprint on Saturday and expanded their search effort in that area.

The RCMP are not considering ending the active search, he said.

“They work on statistical data where how far individuals can go at this point in time and they’ll continue to do what they do,” he said.

“They’re very specialized, trained people here that have the knowledge they need in order to do the best they can.”

Upwards of 160 people took part in the search on Sunday. (Josh Hoffman/CBC)

Earlier Sunday, RCMP Staff Sgt. Josh Wiese, who is leading the ground search and rescue operations, said around 50 searchers, several police dogs and eight drone units looked for the children through Saturday night.

He said the search effort doesn’t stop, with teams rotating in and out. Wiese said there were around 120 searchers Saturday.

“There’s no cellular service, which adds to all of the issues and the safety issues that we have for the searchers and everybody’s pulling for the one goal: they want to find these two little kids as fast as possible,” said Wiese.

He said members of the public can help with the search effort by checking sheds, culverts and ditches on their properties.

“That’s the thing to check, but we just don’t have the capacity to accept walk-up volunteers,” said Wiese. “This is a very managed search.”

Anyone with information about the children is urged to call Pictou County District RCMP at 902-485-4333.