02/10/2012 09:42 EST | Updated 04/11/2012 05:12 EDT

Police in Edmonton to monitor raves, other events, for tainted ecstasy

EDMONTON - Police in Edmonton are warning that tainted ecstasy may have arrived in the Alberta capital.

The warning comes after four non-fatal overdoses at a local electronic music event last month that police believe may have been associated with ecstasy and a compound known as PMMA.

Investigators say the compound is being passed off as ecstasy and has been linked to several deaths in southern Alberta since last summer.

They also say it's impossible to tell what percentage of any drug or chemical makes up the tablet.

Edmonton police say officers will be on hand at all upcoming rave or electronic music events in the city watching for the drug.

A man and a woman, both 19, were arrested earlier this week in Calgary and charged with trafficking in ecstasy laced with PMMA.