The leading international rights watchdog said Monday that immigrant maids in Lebanon are dying of "unnatural causes" at an alarming rate and is calling for an investigation.

At least 95 migrants who worked as domestic servants died in Lebanon since January 2007, mostly in suicides or in botched attempts to escape abuse, Human Rights Watch said.

Domestic workers are dying "at a rate of more than one per week," according to Senior HRW researcher Nadim Houry.

The New York-based group's statement Tuesday also urged Lebanon for a national strategy to reduce the deaths. A report by the group last year criticized several Gulf states and Lebanon for failing to curb abuse and protect migrant women workers.

There are an estimated 150,000 such workers in Lebanon.