At least 26 people have been killed in floods in southern India after heavy rains caused rivers to overflow, cutting off towns and villages.

Five children are among the dead. There are fears the death toll could rise further as many people are missing.

Several houses were washed away and people became trapped in the district of Kottayam in Kerala state.

Video from the area showed bus passengers being rescued after their vehicle was inundated with floodwater.

Kottayam and Idukki are two of the worst affected districts in the state. Days of heavy rainfall has also caused deadly landslides. Swollen rivers have washed away bridges connecting many small villages.

Military helicopters are being used to fly in supplies and personnel to areas where people are trapped, officials said.

Thousands of people have been evacuated and 184 relief camps have been set up across the state, where over 8,000 people are being provided food, bedding and clothing.

The government has also announced financial aid for those who have lost houses and crops.

It has decided to leave the decision of whether various dams in the state should be opened to an expert committee.

In 2018, some 400 people died when heavy rains flooded the state. There was controversy over the fact that dams were opened without any warning to people living in low-lying areas.

Kerala's chief minister Pinarayi Vijayan said that the committee will decide which dams need to be opened.

"District collectors will be notified hours before opening the dams so that local people have enough time to evacuate," his office said in a statement.

Meanwhile, India's meteorological department has predicted heavy, isolated rainfall in the state for up to four more days.

#HADROps #KeralaFloods

Indian Air Force medium lift helicopters have been inducted for #floodrelief efforts in districts of #Kerala inundated due to heavy rains.#HarKaamDeshKeNaam pic.twitter.com/ZcwZRKyYZR

— Indian Air Force (@IAF_MCC) October 17, 2021

Prime Minister Narendra Modi tweeted on Sunday that he had spoken to Mr Vijayan about the situation.

"It is sad that many people have died due to the heavy rains and landslides in Kerala. My condolences to the bereaved families," Mr Modi wrote.

Officials from Alleppey city told BBC Hindi that the situation in the city was worrying. Alleppey has a network of canals and lagoons and it is vulnerable to flooding.

Meanwhile, several tragic stories are coming out from the affected districts.

A family of six - including a 75-year-old grandmother and three children - were confirmed dead after their home in Kottayam was swept away, news agency PTI reported.

The bodies of another three children - aged eight, seven and four - were also found buried under the debris in Idukki district.

Fishing boats are being used to evacuate survivors trapped in Kollam and other coastal towns, as sections of road have been swept away and trees uprooted.

It is not uncommon for heavy rainfall to cause flooding and landslides in Kerala, where wetlands and lakes that once acted as natural safeguards against floods have disappeared because of increasing urbanisation and construction.

The 2018 floods were the worst in Kerala in a century, and displaced more than one million people.

An assessment carried out by the federal government that same year found that the state, which has 44 rivers flowing through it, was among the 10 most vulnerable in India to flooding.