Rabat - (AFP) - The Moroccan authorities announced that they have opened an investigation after a French tourist, suspected of killing his two children in a hotel in Marrakech, attempted suicide.

The investigation, which is being conducted under the supervision of the Public Prosecution, aims to "discover the causes and circumstances of the suicide attempt of a 72-year-old French tourist who is suspected of having premeditatedly killed his two minor children after injecting them with a suspicious substance," according to what the General Directorate of National Security said.

The bodies of the two French minors, aged 9 and 13, were found inside a hotel room in a tourist district of Marrakech.

Their father, a retired nurse, was found next to them in a coma.

According to the first elements of the investigation, the bodies of the two boys did not bear any signs of violence or resistance. And the autopsy is underway.

Also, no evidence of violence was found against the father, who was transferred to a local hospital, where he was admitted to intensive care.

At the site, the investigators found a handwritten letter explaining the motives for the seemingly family tragedy, according to the security source.

Used medical syringes were also found at the site.

The Moroccan judicial police questioned the ex-wife of the French tourist as part of the investigation.