India has threatened to take action against micro-blogging website Twitter over content alleged to have inflamed ethnic tensions against migrants from the northeast, reports said Thursday.

Internet posts, phone text messages and fake video clips are blamed for spreading rumors that Muslims would attack students and workers from India's northeastern region living in Bangalore and other southern cities.

India's opposition vowed on Wednesday to block parliamentary proceedings until the prime minister resigned over a coal scandal, raising the prospect of more legislative deadlock and stalled reforms.

Prime Minister Manmohan Singh was implicated by the national auditor in a report published last Friday which suggested the government had lost out on billions of dollars of revenue by gifting away coal mining rights.

India's prime minister said Friday that the unity of the country was at stake as thousands of migrants from the northeast continued to flee Bangalore and other cities after anonymous threats.

Extra trains were put on for the second night in a row to accommodate panicked students and workers leaving the south and returning to their homes in the northeastern state of Assam.

Thousands of Indians from the northeast of the country have fled southern cities after rumors they would be attacked by Muslims in reprisal for recent ethnic violence, officials said Thursday.

Railway officials said they had put on extra trains from Bangalore to the northeastern state of Assam to accommodate a spike in demand after 6,000 tickets were sold since Wednesday evening.

India plans to launch a space probe that will orbit Mars, Prime Minister Manmohan Singh confirmed on Wednesday after press reports that the mission was scheduled to begin late next year.

The project would mark another step in the country's ambitious space program, which placed a probe on the moon three years ago and envisages its first manned mission in 2016.

The evening turban-tying class in the Sikh-dominated Indian city of Amritsar is packed with pre-teen boys learning a centuries-old tradition -- that religious leaders fear is under threat.

Over the next 90 minutes, the instructors unfurl long strips of cloth in vibrant hues from indigo to burgundy, and proceed to knot, pleat and finally tie them carefully around the boys' heads.

At least 52 people were killed and 45 injured when a heavily overloaded bus plunged into a gorge Saturday in northern India, in one of the worst road accidents in the country in recent years.

The bus, which was carrying over 100 passengers -- many of them on the roof -- veered off the road in a sparsely populated and hilly area of the state of Himachal Pradesh.

Thirty-one people were killed when a passenger bus plunged into a deep gorge Wednesday in a remote part of northeast India, police said.

The packed bus, carrying more than 50 people, skidded off the road and into the gorge before daybreak, in a sparsely populated area of the Indian state of Meghalaya, local police official M.K. Dkhar told Agence France Presse.

Jumpsuits inspired by sari drapes, urban dresses in tribal cloth and digitally printed lehenga skirts -- young designers have re-embraced their Indian heritage at Mumbai's latest fashion week.

In a country that has struggled at times to find its way in the global sartorial stakes, a renewed pride in ethnic traditions has been sauntering down the catwalk.

Indian Sikhs, led by Prime Minister Manmohan Singh, voiced shock and anger Monday at the killing of worshippers at a Sikh temple in the U.S., with some suggesting American Muslims may have been the intended target.

"I am deeply shocked and saddened to learn of the shooting incident that has resulted in the loss of precious lives," the prime minister, himself a Sikh, said in a statement.