NEW DELHI (AFP) - Regional parties on Friday criticised moves by India's new nationalist Prime Minister Narendra Modi to promote Hindi as the government's official language on social media, demanding English be used instead.

The right-wing Bharatiya Janata Party government, which swept to power in May, instructed all ministries and public offices to use Hindi in its official communication on social media last month.

But Ms Jayalalithaa Jayaram, chief minister of southern Tamil Nadu state and whose party is the third-largest in parliament, wrote to Mr Modi on Friday asking him to make English the official language.

"(Push for Hindi) is a highly sensitive issue and causes disquiet to the people of Tamil Nadu," wrote Ms Jayalalithaa, a day after her local rival M. Karunanidhi called the directive an "imposition".

Mr Omar Abdullah, chief minister of Jammu and Kashmir, also voiced his opposition, saying that he regarded English and Urdu as the main languages in what is India's only Muslim-majority state.

"We will continue to use these two languages and whoever wants to use Hindi can. Our country is so huge that you can't impose one particular language on everyone," he told reporters, speaking in Urdu.

India's constitution lists 22 official languages, with Hindi as the main official language and English - the preferred language for business and academics - given associate status.

But according to the last official data, just over 40 per cent of India's 1.2 billion population speak Hindi.

Anti-Hindi sentiment has a long history, especially in southern states such as Tamil Nadu where efforts to impose Hindi triggered bloody riots in the mid-1960s.

Tamil Nadu, born in 1956 of a secessionist movement along linguistic boundaries, uses Tamil and English as its official languages.

In a letter to staff last month, which was leaked to the media, the home ministry said that "prominence should be given to Hindi" on government social media sites.

Home Minister Rajnath Singh, who last year said the use of English undermined Indian culture, tried to defuse anger saying the government was "committed to promote all languages of the country".

But Mr Mukhtar Abbas Naqvi, a spokesman for the BJP, tweeted in Hindi there was a "need to dispel the perception that only English-speakers in the country were intelligent".

Mr Modi, the 63-year-old son of a low-caste tea seller, speaks mostly in Hindi, shunning the English language of the traditional Delhi elite.

However, his posts on Facebook and Twitter are always in English.

On his first foreign trip as premier to Bhutan earlier this week, Mr Modi addressed its parliament in Hindi.

He also reportedly spoke to other leaders of neighbouring countries in Hindi, using interlocutors at his inauguration last month.