Châteauguay police are setting up a command post to solicit more information about the whereabouts of a 51-year-old woman.
Elsa Maria Vargas Valerin was last seen at her home on May 1, around 11 a.m.
A friend reported her missing two days later when she went to pick up her dog from Vargas Valerin, who was looking after the animal.
When the friend arrived at the home, the woman's vehicle was in the driveway and her door was unlocked, but there was no sign of the woman.
Police believe Vargas Valerin left of her own volition, intending to return. They are concerned about her safety.
A few days after Vargas Valerin was last seen, her sister missed a Facetime call from her. When the sister, who lives in Costa Rica, tried to call back, there was no answer and no one has answered since, police say.
The Sûreté du Québec have searched the wooded area behind the woman's home but have not found any clues.
Police say they have received 75 tips so far.
Vargas Valerin, who is originally from Costa Rica but has been living in Châteauguay for 10 years, doesn't have any family in the area.
She is five feet four inches tall, weighs about 210 pounds and has dark hair and brown eyes. She speaks Spanish, French and English.
Police are asking anyone who sees her to call 911. Anyone with information on her disappearance can call 450-698-3229, or visit the command post at Paroisse Marguerite-D'Youville on Rainville Street until 3 p.m.