The Indian government on Thursday told the Supreme Courtinfo-icon that Rohingya refugees were "a threat to national security", pushing back against condemnation of its plans to deport them.

Indiainfo-icon's top court is hearing a challenge to Prime Minister Narendra Modi's government's decision to deport Rohingya Muslims, filed by two Rohingyas living in Delhi who fled their village in Myanmarinfo-icon's western Rakhine State about six years ago.

The decision to deport Rohingyas comes as Myanmar's military crackdown in Rakhine has forced hundreds of thousands of Rohingyas to seek shelter in Bangladeshinfo-icon, in a process the UN has described as ethnic cleansing.

Close to 40,000 Rohingya Muslims live in India after fleeing Myanmar over the past decade. Nearly 15,000 have received refugee documentation, according to the United Nationsinfo-icon, but India wants to deport them all.

Some groups allied to Modi's Bharatiya Janata Party have stepped up calls for Rohingyas to leave, and Modi said last week that India shared Myanmar's concerns about "extremist violence" in Rakhine state.

On Thursday, a senior lawyer representing India's government told the supreme court that "the state considers that Rohingyas are a threat to national security".

Intelligence agenciesinfo-icon suspect that Rohingya Musliminfo-icon leaders in India are in touch with Pakistaninfo-icon-based militant groups, the lawyer said.

Aid groups and human rightsinfo-icon activists have criticised the plans to expel Rohingyas, and some lawyers say deportation would violate India's constitution.

India's supreme court is expected to start hearing the case on Monday.

India this week sent 53 tonnes of relief materials to Bangladesh for Rohingyas fleeing Myanmar.