"We have stepped up surveillance and patrols so that no Rohingya can be pushed into our territory," Lieutenant Colonel Hakim told AFP.
There are 40,000 Rohingya in India but the Indian government wants them deported, telling a top court last month they pose a security threat.
Hakim said Rohingya communities inside India could be trying to reunite with their families in southeast Bangladesh, where more than half a million Rohingya refugees have arrived since August from Myanmar.
An estimated 536,000 refugees have crossed since August 25, fleeing violence in western Myanmar described by the United Nations as ethnic cleansing.
An Indian border guard in West Bengal told AFP that patrols had previously turned over all Rohingya intercepted at the frontier to local police.
"But now our directions are very clear, and that is to push all Rohingya into Bangladesh," he told AFP on condition of anonymity.
"We are trying to accomplish our task with active local support".
A Bangladesh border guard official, Abdul Hossain, said villages along the frontier were on high alert, with newly-arrived refugees saying they had been encouraged by Indian guards to cross the border.
"We've been patrolling the border day and night to prevent their entry. Local villagers have also joined us in the patrols," Hossain told AFP.
Local council member Nazrul Islam said more than a dozen Rohingya who crossed at a southwestern part of the frontier Friday reported Indian guards opening a section of barbed wire to allow them to pass easily.
Bangladesh already hosts at least 800,000 Rohingya, including those who fled earlier crackdowns in Myanmar, and does not want to accept any from India.
It is trying to repatriate the Rohingya to Myanmar. But the stateless Muslim minority are reviled in the mainly Buddhist nation and considered to be illegal immigrants.
The unprecedented influx of refugees has put immense pressure on Bangladeshi authorities and charities, who have described the crisis as one of the world's most pressing humanitarian emergencies.
Also watch below: Nowhere men, the Rohingya of Myanmar
Some 40,000 of the world's 'most persecuted minority' live in India (WION)