More than 400 volunteers are combing farm fields and wooded areas in rural south-central Manitoba on Friday in the search for Chase Martens, a toddler who has been missing since Tuesday evening.

The two-year-old boy disappeared from his farm home near Austin, Man., about 120 kilometres west of Winnipeg.

Volunteers and trained search and rescue personnel scoured the fields and woods around the community starting at 9 a.m. CT Friday, after the search was suspended late Thursday evening.

Crews were joined by RCMP drones that are photographing and mapping the area.

Chase Martens

Chase Martens is described as 2½ feet tall and 30 pounds with blue eyes and light brown hair. He was last seen wearing a blue jacket, black splash pants, a red hat and boots that light up as he walks. (RCMP)

The search area was expanded on Friday afternoon to a four kilometre radius from the location where the boy was last seen, up from three kilometres earlier in the day, according to RCMP.

Police tweeted late in the afternoon that "well over 400" people came out on Friday. Police had said they were expecting a large number, given many people have the day off for Good Friday.

There were about 395 volunteers and trained searchers on Thursday and upward of 500 on Wednesday, according to police.

Among the volunteers who came out on Friday was Liza-Jane Krieter of Brandon, Man., who said she is thinking of Chase's family and her own four-year-old son back home.

"I couldn't imagine what they're going through. So many things could happen out here, you know. And all these people are coming out to help, and that's all you can do," said Krieter, who was also involved in the search on Thursday.

Below-freezing temperatures

Following a couple weeks of warm weather, temperatures have dropped below freezing in the Austin area each night since the boy was reported missing, prompting search and rescue officials to issue an urgent plea for help in the search from residents in and around the community.

Temperatures in the area have been just under 0 C on Friday. A thin layer of snow that fell overnight dusted the ground as searchers arrived in the morning.

Drone surveillance and an underwater recovery team were added to the efforts Thursday.

RAW: Manitobans search for missing toddler Chase Martens through snow, darkness Thursday night0:43

On Friday, RCMP said the underwater team has left but remain available to deploy if needed to search a specific area.

Chase is described as 2½ feet tall and 30 pounds, with blue eyes and light brown hair. He was last seen wearing a blue jacket, black splash pants, a red hat and boots that light up as he walks.

RCMP are asking anyone with information about his whereabouts to contact their local police department.

Chase Martens search

Searchers line up to walk through some brush as part of Thursday's efforts to find Chase Martens. (Trevor Brine/CBC)