NEW DELHI -The stellar showing by the Bharatiya Janata Party (BJP) in state elections in the northeastern states of Tripura, Nagaland and Meghalaya on Saturday showed the party is successfully widening its sphere of influence from northern and central India, said analysts.

The BJP won by a landslide win in the state of Tripura, ending over two decades of rule of the Communist Party of India (Marxist).

In the other two Christian majority states of Nagaland and Meghalaya, the BJP came to power in savvy alliances with local parties.

In scoring these victories, the BJP, led by Prime Minister Narendra Modi and party president Amit Shah, now holds power in 21 out of 29 states, and has displaced the Congress as the pan-India party, said analysts.

Nagaland was earlier ruled by an alliance led by the Naga People's Front and included the BJP, while Meghalaya was ruled by the Congress.

"Clearly, this is the political footprint of the party being spread all over the country," said Dr Sandeep Shastri, a political analyst and pro-vice-chancellor of Jain University.

"The Northeast win is an important indicator of the Prime Minister's image and popularity."

Mr Modi, wearing the local headgear and scarf, addressed rallies in all the three states, while The Hindu newspaper called it the "saffron breeze" - the colour of BJP's flag - in the Northeast.

The stronghold of the BJP has traditionally been in northern and central India, its identity forged in Hindu nationalism and through flash points such as building a temple to the god Rama on a disputed site and protecting the cow, revered by Hindus.

Since coming to power in 2014, it has been able to expand its influence to most parts of the country at the cost of the Congress, led by members of the Gandhi-Nehru family.

Analysts said the BJP had built its presence in the Northeast over the last four years through a combination of deft political manoeuvring, the focus on an economic agenda and the popularity of Mr Modi.

In Meghalaya, the Congress won the 21 seats in the 60 seat assembly but still lost out to the BJP, which won only two seats but managed to stitch together a winning alliance, wooing the United Democratic Party, which won six seats.

"This is the outcome of sustained effort on the part of the BJP to build an organisation in Northeast. Speeches by leaders of BJP focused on issues of employment, lack of facilities and better pay for government employees," said Professor Bidyut Chakrabarty, a political science professor at Delhi University.

The same spotlight on bread and butter issues was shone elsewhere, he said, noting: "In Tripura, it was the economic agenda which brought the BJP to power. It was not won on any religious issue.

"Nowadays, the BJP has the reputation of giving good governance...it is in power in over 20 states and has become a pan Indian party, which is far ahead of the Congress."

Congress president Rahul Gandhi yesterday accepted defeat in the Northeast, tweeting: "The Congress party respects the mandate of the people of Tripura, Nagaland and Meghalaya. We are committed to strengthening our party across the North East and to winning back the trust of the people."

The northeastern states are connected to the Indian mainland by a narrow stretch of land known as the Siliguri corridor or "Chicken's neck".

The Northeast, comprising eight states, has always been distinct from the rest of India due to its geographical position and culture. Its people have felt that successive federal governments have ignored developments in the region, an issue Mr Modi promised in successive state elections to remedy.

On Sunday, he asserted the BJP had brought the Northeast into the mainstream.

"For the first time, the rest of India was closely monitoring the north-east poll results. It proves that the nation is being united. It is a big change," Mr Modi said at a conference.

The BJP also won elections in the northeastern states of Assam in 2016 and Manipur in 2017.