Homes have been evacuated along a west Ottawa street as police conduct a lengthy, mysterious investigation into the possibility of explosives in one of the homes.

Ottawa police have been investigating something on Arbordale Crescent in Nepean starting Wednesday night, but didn't say it could be explosives until the next day.

Fourteen homes have been evacuated as a precaution, with one man in custody who hasn't been charged.

Tactical and Haz-Mat teams were on the scene when the operation started.

Arbordale Crescent is closed at both ends while the investigation continues.