More than 350 people have died and hundreds of thousands have been displaced from their homes amid what has been described as the worst floods in the southern Indian state of Kerala in a century. 

Rescue teams were working to save thousands of people who remain marooned with the state's Chief Minister Pinarayi Vijanyan reportedly vowing on Sunday to "save even the last person stranded".

Floods in India

PICTURE: Church of South India

Whole villages have been demolished in landslides and the military was helping to clear debris and restore transport links.

Bidisha Pillai, CEO of Save the Children India, said late last week that the state hadn't seen flooding like this for decades and said that amid reports of damage to major infrastructure and homes, schools were being used to shelter the displaced.

“We’re especially concerned about the welfare of children, who are more at risk of being swept away by floodwaters," Pillai said. "Thousands of families are staying in evacuations centres, not knowing what will be left of their homes when they return. This can be a frightening ordeal for anyone to go through, but this is especially so for children.”

Amitabh Behar, CEO of Oxfam India, expressed concerns over the rising death toll. 

"The situation is grim but the scale of the tragedy will not be clear until affected areas become more accessible," Behar said. "While rescue and relief are the priority in the short term, the enormity of this catastrophe means on-going support will be needed with recovery, rehabilitation and reconstruction."

Behar added that the international community will need to "back the efforts" that India's Government and people were making in response to what was an "unprecedented crisis".

Rev Dr Olav Fyske Tveit, general secretary of the World Council of Churches, has called for prayer for those affected by the floods.

“Our hearts go out to people living in terrible fear in what has become a precarious situation,” he said, noting that local churches had become "especially important in bringing hope to remote villages cut off by flooding that has destroyed roads and bridges".

“We also hear reports of damage to churches and relief centres, and we pray for those trying to respond even while coping with their own losses.”

The Church of South India has reported that church buildings and mission centres have been damaged or destroyed.