Indians were flying aeroplanes, carrying out stem cell research and may even have been using cosmic weapons 5,000 years ago, according to the chairman of India's leading historical organisation.

Professor Y Sudershan Rao, the head of the Indian Council of Historical Research, has been criticized by fellow historians for comments that Hindu epics are adequate to understand the ancient world, rather than relying on evidence or research.

The Hindu nationalist government appointed Rao to the prestigious academic post soon after winning the biggest landslide in three decades, fuelling concerns of a push to teach the superiority of Hindu values and mythology at the cost of academic rigour, and cutting against the grain of secularism that runs through multi-faith modern India.

"We have so many proofs that these events happened," Rao, 69, said in an interview, describing events in the Mahabharata and the Ramayana, the ancient Hindu epics about love and war, truth and deceit, that feature characters using inextinguishable fire and weapons with the destructive power of a nuclear arsenal.

Similar views have won support from Prime Minister Narendra Modi and in part reflect a belief that India's history books are beholden to colonial powers, foreign invaders and Marxists.

While there is debate over the exact age of the Hindu epics, historians say they were probably written at least two millennia ago. Rao says this in itself is proof the texts are factual because humans did not develop the art of fiction writing until a few centuries back.

Many academics are horrified by such views, and describe his appointment as a blow for the history organisation set up four decades ago to guide research and hand out grants. They point to signs of a broader plan to bring more Hinduism to the classroom through changes to the curriculum.

Two Indian states run by the ruling Bharatiya Janata Party have recruited controversial Hindu nationalist Dinanath Batra to advise on writing textbooks.

In June, thousands of schools in Gujarat were given textbooks by Batra that claimed cars were invented in ancient India and told children to draw an enlarged nation to include countries including Pakistan, Bangladesh and Afghanistan.

Teachers at Batra's organisation say they want the books to be in every school.

"The lessons from today's history books are that Indians are nothing and good for nothing," said Atul Kothari, secretary of Batra's Shiksha Bachao Andolan Samiti, or Save the Education Movement. "The truth is that historically we have been a far superior race."

Education Minister Smriti Irani, a former soap actress, declined to comment on what revisions will be included in a review of the curriculum planned next year.

The last time the ruling Bharatiya Janata Party was in power a decade ago it began to rewrite school books in line with Hindu-nationalist orthodoxy.

When the rival Congress party came back to power it rewrote the books again. Academics say the loser in all this are confused, and sometimes ill-informed, school children.

Modi is the first prime minister to publicly back the view that holy texts show many discoveries of modern science were made by ancient Indians. He told an audience of doctors last month that the Hindu god Ganesh's head was evidence of ancient plastic surgery. A warrior the Mahabharata describes as born outside his mother's womb was a test-tube baby, Modi said.

"These claims can be interpreted as signs of an inferiority complex," said Romila Thapar, a leading scholar on ancient India. "The most disturbing thing is that many people accept this without questioning it," said Thapar, whose books one BJP leader has said should be burned.