Military helicopters dropped emergency supplies Wednesday to thousands of tourists and pilgrims stranded by flash floods that tore through towns and temples in northern India, killing at least 138 people, officials said.

Thousands of people have already been evacuated after floods and landslides caused by early monsoon rains wrought devastation through the region in the Himalayan foothills, they said.

Torrential rains have washed away hundreds of homes and roads, leaving at least 64 people dead and thousands stranded, after the annual monsoon hit northern India earlier than expected, officials said Tuesday.

The Indian Air Force scrambled a dozen helicopters to reinforce a military-backed rescue mission in the worst-hit state of Uttarakhand, a spokesman said.

Heavy rains lashed parts of north India Monday, resulting in the deaths of at least 26 people, as the annual monsoon covered the country nearly two weeks ahead of schedule, officials said.

Surprise showers struck the capital New Delhi over the weekend, flooding the arrival halls in the international and domestic airports and leading to traffic jams in some parts of the city.

An overcrowded ferry which was packed with dozens of people and livestock capsized Friday in the Indian state of West Bengal, killing at least two and leaving 25 others missing, officials said.

"At least two people died and 25 are missing after a ferry capsized in the Ganges," Sabitri Mitra, a government minister who is overseeing the rescue operation told Agence France Presse.

Maoist guerrillas opened fire on a passenger train in the eastern Indian state of Bihar on Thursday, killing one police officer and two passengers, police said.

Around 100 guerrillas forced the train to stop as it was traveling from the town of Dhanbad to the state capital of Patna and then opened fire, senior police officer Amitabh Das told Agence France Presse.

Pakistan on Tuesday accused Indian jets of briefly violating its airspace, days after India said one of its soldiers had been killed by Pakistani troops.

The Pakistan Air Force said it scrambled two fighter jets after two "high-speed" Indian planes crossed the border over its eastern province of Punjab at about 10:40 am (0540 GMT).

An apartment block collapsed in central Mumbai on Monday evening, killing at least one person with more feared trapped inside, police said, on the second day of heavy monsoon rains in the city.

"We have information that one person is dead. Rescue operations are on, but they are difficult due to the heavy rain," a police inspector in the Mahim neighborhood, where the collapse happened, told Agence France Presse.

Veteran Indian opposition leader Lal Krishna Advani resigned on Monday, a day after his party chose hardliner Narendra Modi to lead next year's election campaign, a source in his office told Agence France Presse.

Advani, the 85-year-old stalwart of the Bharatiya Janata Party (BJP) and a former deputy prime minister, resigned from all his positions within the party, the source said.

At least 18 tribal villagers in India's northeast were arrested for hacking to death a man they suspected of practicing witchcraft, police said Saturday.

They claimed they were told to kill the victim by a Hindu goddess who appeared in their dreams.

Indian police said they arrested three men Thursday over the gang-rape of a U.S. tourist who was attacked after she hitched a ride in a truck.

The 30-year-old American accepted a lift on Monday night in Manali, a tourist destination in the foothills of the Himalayas, after struggling to find a taxi to return to her hotel.