Warnings about the risk of overdosing have been issued by NHS Highland
The deaths of two men and a woman since the start of the month in Inverness are being investigated by police and the procurator fiscal service.
Police said the incidents were thought to be drug-related, but there was no evidence to suggest they were linked.
NHS Highland has issued a warning to people who inject illegal drugs to take precautions to avoid the risk of overdosing.
Last year, the authorities probed the deaths of five drug abusers.
Following the latest incidents, NHS Highland's director of public health Dr Eric Baijal said: "The death of any young person is a tragic loss. Our sympathies go out to their families and friends.
"The agencies providing help and support to users are constantly offering advice on how to reduce the harm, including advice not to take drugs in combinations or alongside alcohol, but ultimately there is no way to make injecting drugs completely safe."
http://news.bbc.co.uk/1/hi/scotland/highlands_and_islands/8056995.stm