A day of prayer and fasting will be held on Thursday for a group of 17 missionaries and children kidnapped in Haiti.

Christian Aid Ministries (CAM) said it was praying for their safe release, as well as for the kidnappers to turn to Christ.

The group is formed of 16 Americans and one Canadian, and includes five children, the youngest of which is just 8 months old. 

They were kidnapped near capital Port-au-Prince on their way back from visiting an orphanage supported by CAM. 

The gang behind the kidnapping, 400 Mawozo, has demanded $17m for their release.

The US-based non-profit said it was working closely with government authorities to bring the group home. It has not commented on whether it will meet the ransom demand.

Asking people to pray and fast, CAM said: "We invite continued prayer for: the victims—for endurance, faithfulness, and a spirit of Christlike love ... the kidnappers—that they would experience the love of Jesus and turn to Him [and] government leaders and authorities—as they relate to the case and work toward the release of the victims."

CAM is also asking for prayer for Haiti.

"This time of difficulty reminds us of the ongoing suffering of millions of Haitians," it said.

"While our workers chose to serve in Haiti, our Haitian friends endure crisis after crisis, continual violence, and economic hardship.

"Despite the difficulties and dangers involved in working there, both our Haitian and American workers carry a vision to minister the love of Jesus in Haiti.

"Our goal is to seize opportunities around the world, even in difficult contexts, to follow in the footsteps of Jesus, who 'went about doing good' (Acts 10:38)."