AMSTERDAM, Netherlands – Health authorities in Amsterdam are warning of dangerous drugs being sold to tourists after three British men **** in the last month after snorting ****** they may have believed was *******.

A large sign outside the Dutch capital’s Central Station warned Thursday, “Extremely dangerous ******* is sold to tourists” in the area.

The warning campaign was started after two British men, aged 20 and 21, were found **** in a hotel room in the city on Tuesday. ****** say they likely **** after snorting “white ******” they likely bought believing it was *******.

Amsterdam ****** spokesman Rob van der Veen says the same **** is suspected in another British tourist’s ***** last month.

Van der Veen says it is not yet clear why ****** is apparently being sold as *******.