A mysterious pair of pigs spotted in Burnaby, B.C., Saturday remained elusive overnight.

The pigs were seen cavorting around a residential neighbourhood not zoned for swine.

Burnaby resident Horatio Vale was with his daughter when he spotted them Saturday on Manor Street, between Royal Oak Avenue and Wayburne Drive sometime after 4 p.m. PT.

Burnaby SPCA manager Ryan Voutilainen said they did several patrols, but there was no sign of the pigs.

"It's not common that you see pigs in the City of Burnaby, and that area where they were roaming isn't zoned for pigs," he said.

He suspects somebody may have been babysitting some pet pigs and they escaped.

"Pigs tend to be very smart, so if they can find a spot to get out and get away and go investigate ... they will."

Pigs un-penned in Burnaby. Video c/o Horatio Vale. More at 10:30pm <a href="https://twitter.com/CBCVancouver">@cbcvancouver</a> News with <a href="https://twitter.com/LienY">@LienY</a>, right after <a href="https://twitter.com/hockeynight">@hockeynight</a>. Ch3/HD209 <a href="https://t.co/ccOl423Nbt">pic.twitter.com/ccOl423Nbt</a> —@DanBurritt

The B.C. SPCA said it received multiple calls about the pigs on Saturday, but looking for them wasn't easy.

An officer with the SPCA said the residential area they were spotted in had a lot of places for them to hide and it was difficult to keep track of where they were.

Anyone who sees the animals is asked to call in their location.​