Indian Prime Minister Narendra Modi waves as he takes part in a run for unity after flagging it off to mark the birth anniversary of Indian freedom fighter and a lawmaker Sardar Vallabhbhai Patel, in New Delhi on Friday.

AFP/New Delhi

India's president Pranab Mukherjee, members of Nehru-Gandhi family and Congress leaders paid a low-key tribute on Friday to Indira Gandhi on the 30th anniversary of the ex- premier's assassination.

No ministers of India's new government attended the event honouring Gandhi, gunned down by Sikh bodyguards on October 31, 1984, in retaliation for ordering an attack on a revered Sikh shrine to clear out militants holed up in the complex.

"I join my fellow countrymen and women in remembering former PM Indira Gandhi" on the anniversary of her death, right-wing Premier Narendra Modi tweeted to his 7.4mn followers.

But for the first time, no government representative attended the annual ceremony at the rose-strewn Gandhi memorial, local media reported.

Indira Gandhi's daughter-in-law Sonia, 67, who cradled the leader's head in her lap as she bled to death, led those paying tribute.

Sonia, dressed in a sombre black-and-grey sari, was accompanied by her son, Rahul, 44, heir to the Congress dynasty, which dominated India's post-independence politics.

Sonia and Rahul, who led the party to its worst-ever defeat in May elections, pressed their palms together in a traditional Indian gesture of "namaste" in front of Indira's memorial.

While staying away from the event marking Indira's death, Modi and cabinet ministers flagged off a "run-for-unity" near the India Gate war memorial in the capital's heart.

The run marked the birth of freedom fighter and Congress leader Sardar Vallabhbhai Patel, India's first home minister, who forged a united republic out of patchwork of princely states after independence from Britain in 1947.

Patel, deputy of India's first prime minister, Congress leader Jawaharlal Nehru who was Indira's father, "is truly the architect of modern India", Modi tweeted.

The high-profile government turnout for Patel contrasted with the muted ceremony for Indira, a hugely popular but also divisive figure, known as the "Iron Lady" for her strong leadership qualities.

The run-for-unity was another tribute to Patel by Modi's Hindu nationalist Bharatiya Janata Party, which has appropriated Patel as a national unity symbol in what analysts said was part of a bid to break Congress's traditional hold on Indians.

Earlier this year, Modi allocated $33mn in government funds to help build a 182-metre statue of Patel that will be the world's tallest statue.