Colourful lights decked up buildings and diyas (earthen lamps) dotted houses as people across the country celebrated Diwali with great enthusiasm on Thursday.

In the national capital, the air quality continued to deteriorate, remaining in the 'very poor' category, with levels expected to worsen to the 'severe' category due to bursting of firecrackers at night.

Keeping up his tradition of celebrating the festival with soldiers, Prime Minister Narendra Modi visited Sir Creek near the Indo-Pak border in Gujarat's Kutch district and offered sweets to jawans.

Modi said India cannot compromise on even an "inch" of land on its borders, adding the people believe in the strength of its armed forces for defending the country.

"In the past, attempts were made to turn this region into a battlefield. The enemy has set its eyes on this region for a long time. But we are not worried as you are guarding the nation. Our enemy also knows it well," he asserted.

"People of India feel their country is safe because of you; when the world sees you, it sees India's strength, when enemies see you, they see the end of their sinister plans," the Prime Mnister said, addressing personnel of the Border Security Force, Army, Navy and Air Force.

He also said that "we see the Army, Navy and Air Force as different entities, but their strength will increase manifold when they come together."

As the country is moving fast towards the goal of developed India, "you all are protectors of this dream," Modi told the soldiers.

One of the most popular Hindu festivals, Diwali is associated with the day Lord Ram is believed to have returned to Ayodhya with his wife Sita and brother Lakshman after defeating demon king Ravana during his 14 years in exile. The festival is seen as a celebration of the victory of good over evil.

Dressed in traditional attire, people greeted each other, exchanged sweets and gifts, and visited temples.

The celebrations across the country were largely incident free. However, in Uttar Pradesh, six people, including four of a family, were killed when a tempo they were travelling in was hit by a tractor in the Mujaria area of Budaun, police said. The victims, who worked as vegetable vendors in Noida, were returning home to celebrate Diwali.

In Andhra Pradesh, a man died after the firecrackers he was carrying on a two-wheeler exploded in Eluru town, police said.

In UP, Chief Minister Yogi Adityanath celebrated Diwali with the forest dwellers of Vantangiya village in Gorakhpur.

He said people dividing society along caste, regional, and linguistic lines have the "DNA of Ravan and Duryodhan", and warned that anyone who attempts to disrupt peace or get involved in crime against women would be dealt with strictly.

"If we get deceived by such forces and give them a chance, they will again do the same thing... They threaten the safety of daughters and sisters, usurp the land of the poor, kidnap businessmen, shoot people on the road and incite riots before festivals. This is what these people used to do before 2017," he said, in an apparent attack on the previous Samajwadi Party government in the state.

During his visit to the area, the chief minister inaugurated 74 development projects valued at ₹185 crore across various gram panchayats.

In the national capital, Delhiites woke up to a sky shrouded in a thick layer of smog. The air in Anand Vihar, a major terminus, was extremely polluted with the AQI in the "severe" category.

The city's 24-hour average Air Quality Index (AQI) was recorded at 328 at 4 pm, up from 307 on Wednesday when the city celebrated Chhoti Diwali.

In 2023, Delhi residents enjoyed clearer skies and abundant sunshine on Diwali, with an AQI of 218.

In accordance with the practice of the past four years, Delhi has announced a comprehensive ban on the manufacture, storage, sale and the use of firecrackers in the city.

In Uttarakhand, Chief Minister Pushkar Singh Dhami visited the Lansdowne cantonment to celebrate Diwali with army soldiers, saying he felt "fortunate" to be with them on the auspicious occasion.

Paying tribute to the martyrs by offering a wreath at the war memorial there, Dhami said, "We can light diyas at our homes on Diwali only because our brave soldiers live away from their families to protect the country's borders." Dhami also distributed sweets and gifts among the soldiers, widows of martyrs and their children.

In Rajasthan, the festival of light was celebrated with great enthusiasm. Markets were vibrant and bustling until late Wednesday night with people flocking to buy new clothes, sweets, firecrackers and other festive items.

CM Bhajanlal Sharma and other leaders extended Diwali greetings on X.

Meanwhile, more than 20 lakh devotees gathered at Chitrakoot on the border of Madhya Pradesh and Uttar Pradesh on the occasion of Diwali, an official said.

According to mythology, Lord Ram spent the better part of his 14-year exile at Chitrakoot, located on the banks of the Mandakini river.

Devotees took a dip in the river and performed `deep-daan' ceremony.

In Odisha, Chief Minister Mohan Charan Majhi wished people on the occasion of Diwali and emphasised his government's commitment to take the state to new heights.

"My heartiest congratulations to all the brothers and sisters of Odisha on the occasion of Diwali, the festival of light and joy," Majhi said in a video message on his X handle.

In the coastal state of Goa, the celebrations took off after the burning of Narakasur demon effigies in the early hours.

As per traditions, the effigies were taken around before they were burnt to mark the victory of good over evil.