IRNA � President Hassan Rouhani in a message to his Azerbaijani counterpart Ilham Aliyev late on Friday offered condolences over deaths caused by fire incident in a treatment center in Baku.

'The sorrowful news of death of a number of citizens of the friendly and brotherly country of the Republic of Azerbaijan in a fire incident in a treatment center in Baku saddened me,' read the message.

'Offering condolences to the dear brother and expressing sympathy with families of the victims of the painful incident, I wish good health and success to Your Excellency and the noble nation of Azerbaijan,' he said.

A fire killed 30 people at an addicts rehabilitation center in Azerbaijan's capital Baku. The cause of the incident is not clear yet and investigations are underway.