India is using “chilli and stun grenades” to block the entry of Rohingya Muslims fleeing persecution  in Myanmar, reports quoting officials said on Friday.

Border forces in India, which wants to deport around 40,000 Rohingya already living in the country, citing security risks, have been authorised to use “rude and crude” methods to stop any attempts by the Rohingya to cross the India-Bangladesh border, news agency Reuters reported.

“We don’t want to cause any serious injury or arrest them, but we won’t tolerate Rohingya on Indian soil,” said a senior official with the Border Security Force (BSF) in New Delhi.

“We’re using grenades containing chilli spray to stop hundreds of Rohingya trying to enter India … the situation is tense,” added the official, who declined to be identified as he was not authorised to speak to media.

More than 420,000 Rohingya have fled to Bangladesh since August 25. The UN has called Myanmar’s assault on Rohingyas a “textbook example of ethnic cleansing”.

Bangladesh is struggling to shelter all the refugees desperate for space to set up shacks, sparking worries in India that the influx could spill into its territory.

R.P.S. Jaswal, a deputy inspector general of the BSF patrolling a large part of the border in West Bengal, said his troops were told to use both chilli grenades and stun grenades to push back the Rohingya.

A chilli grenade makes use of a naturally-occurring compound in chilli powder to cause severe irritation and temporarily immobilise its target.

Prime Minister Narendra Modi’s government is growing increasingly hostile towards the Rohingya in India, with home minister Rajnath Singh calling on Thursday for their deportation as “illegal migrants”.

Seeking to get legal clearance for the deportation plan, the home ministry told the Supreme Court this week it would confidentially provide it with intelligence information showing Rohingya links with Pakistan-based militants.

Most of the refugees had no link to criminal activity, two Rohingya men protesting against the deportation move told India’s top court on Friday.