Should i call the fire fighters?

I live in a townhouse so most of the houses are close to each other, and a house some where close to mine has a carbon-monoxide or a fire alarm that's been beeping for about 2 days. I think that the people that live there are on vacation or out of the house for a while because the alarm has not been turned off. personally i think it's a carbon monoxide alarm because if it was a fire the house would have burned down in two days. So should i call the firefighters or the police?