The Indian government deployed the army at four locations in Bengal near the Bangladesh border on Monday soon after the downfall of the Sheikh Hasina government in the neighbouring country.

The BSF, which guards the border, stepped up the vigil amid a halt in the movement of goods and passengers between the two nations.

Sources said as an additional security measure, the army had been positioned near the India-Bangladesh border at Petrapole in North 24-Parganas, Changrabandha in Cooch Behar, Fulbari in Jalpaiguri and Hili inSouth Dinajpur.

Fulbari is located near Siliguri, which is a part of the “chicken’s neck” or the Siliguri corridor — the slimmest part of India, sandwiched between Nepal in the north and Bangladesh in the south.

“The deployment of the army near the border has been made to mitigate any potential security threat as a volatile situation is prevailing in Bangladesh. Also, the BSF has deployed additional forces along the border to intensify vigil and prevent any unlawful activity, including infiltration,” said a source.

The density of the deployment has increased along several unfenced and riverine borders, said the source.

“At these vulnerable places, one jawan each has been deployed for every 10 metres,” the source said.

Bengal has some unfenced and riverine stretches along the Bangladesh border.

“Specific instructions have been passed to maintain intensive surveillance round the clock in these areas. Also, information received from the ground is being shared with all agencies concerned,” the source said.

As Hasina resigned and flew to India, glimpses of protests and jubilations were witnessed across the border near land ports like Hiliand Fulbari.

Earlier in the day, BSF’s newly appointed director general, Daljit Singh Chaudhary, arrived in Calcutta to review the border situation and discuss the strategic scenarios and operations with the Eastern Command of the Indian Army.

“Two platoons of the army have reached near the New Changrabandha station, which is around one-and-a-half kilometres from the border. Similarly, army personnel have been stationed in nearby locations of Petrapole and Fulbari,” said a source.

The bilateral trade between the two countries also halted following the unrest in Bangladesh.

On Monday morning, despite the tension, trade had commenced with 156 trucks entering Bangladesh via Petrapole and over 140 trucks entering the neighbouring country via Mahadipur in Malda.

When the situation became volatile by afternoon, the trade stopped at the land ports at Ghojadanga in North 24-Parganas, Changrabandha, Fulbari, Mahadipur and Hili.

Trucks carrying various items, including perishable items, are stranded on the border at all the land ports.

The exporters and clearing agents at the land ports apprehend that they will incur huge losses as there is no indication of when the trade will resume. They said they were equally concerned over the safety of their vehicles and driversin Bangladesh.

“This is an unexpected development in Bangladesh and we don’t know when our vehicles will return to India. We hope the Bangladeshi army will ensure the security of our goods, vehicles and drivers,” said Kartick Chakraborty, secretary, of Petrapole Clearing Agents Staff Welfare Association.

In the evening, around 190 Indian truck drivers,who were left stranded in Bangladesh, returned via Changrabandha.

People continued to pass through the border till late afternoon when the borders were completely sealed.

“I went to Bangalore and returned today. I have no idea how I will reach home as there has been a rapid change in the situation of my country,” said Mohammad Shaon, a youth from Rajshahi district who reached Mahadipur to return to his homeland.