At least 15 people have died as a bus carrying pilgrims overturned in northeastern Brazil, according to local officials.

The vehicle was transporting about 60 individuals returning from a pilgrimage when it crashed on a curved stretch of highway in the rural interior of Alagoas state on Tuesday morning.

Among the deceased were three children, while some surviving passengers were airlifted to hospitals for medical attention.

Social media footage depicts the bus on its side, surrounded by debris and emergency crews attending to the scene.

An investigation has been initiated, with authorities suspecting that the driver lost control of the vehicle, causing it to leave the highway and roll over multiple times.

Reports indicate that the most seriously injured individual transferred to the hospital is a nine-year-old child who sustained a head injury.

The passengers were partaking in the pilgrimage of Our Lady of Candeias, a significant religious festival in the state of Ceará.

The bus belonged to a larger convoy transporting hundreds of people from the city of Coité do Noia in Alagoas to Juazeiro do Norte in Ceará, a journey that typically takes around eight hours.

The tragedy unfolded in São José da Tapera on the last segment of their return journey to Coité do Noia.

Bueno Higino Filho, the mayor of Coité do Noia, expressed his sorrow, stating, The loss is immense. They were all my friends... I woke up today to the sad news and I'm heading to the site of the accident to see what we can do [to help]. Three days of mourning have been declared by the governor of Alagoas state.

Governor Paulo Dantas expressed his condolences on social media, stating, I stand in solidarity with the family members and friends in this moment of such great pain.