Heavy rain in Bihar has thrown life out of gear in Patna and other places.

Saying that the situation in Bihar had gone "out of control" after heavy rainfall in the state, Congress leader Rahul Gandhi on Monday appealed to party workers to join the relief-and-rescue efforts to help the affected people.

After being pounded by heavy rain over the weekend, most parts of Bihar's capital city Patna remained submerged. Twenty-seven people have reportedly died in the state in rain-related incidents.

"The situation arising out of the Bihar floods has gone out of hand with the news of many deaths," Mr Gandhi said in a tweet in Hindi.

"I express my condolences to the families of the deceased and appeal to the Congress workers to immediately join the relief-and-rescue work to help the affected people," the former Congress president said.

Heavy rain in Bihar has thrown life out of gear in Patna and other places. Bihar Deputy Chief Minister Sushil Kumar and his family were rescued from their home after up-scale residential areas like Pataliputra Colony and Rajendra Nagar were submerged under several feet of water.

Bihar Chief Minister Nitish Kumar, whose JDU government has asked the Indian Air Force for help, drove through affected localities in Patna this morning to survey the situation.