A three-year-old girl and her smiling big sister have died after they were apparently accidentally poisoned.

The three-year-old girl, named as Razan, was taken to the Sidon Governmental Hospital in Sidon, Lebanon, last week after falling ill.

Her big sister, whose age was not reported but who was named as Rayan Walid Saleh was also poisoned, as were their parents.

Rayan was transferred to Hammoud University Hospital due to the seriousness of her condition but she sadly succumbed as well.

The Hajj Bahaa al-Din al-Hariri school, which Rayan attended, is mourning its tragic pupil.

They reportedly offered their condolences to the family over the young girl’s death and that of her sister.

Her seat at school was left empty, with a photograph of her put there.

The head of the school, the administration, teachers and colleagues, who missed her at the beginning of school hours, remembered her by holding a minute of silence and saying a prayer for her.

They said they would always remember Rayan and her smile.

There have been no updates on the parents’ medical condition.

The authorities are currently investigating the cause of the poisoning, which remains unclear.