Mexican immigration authorities say they have deported 311 Indian citizens in an unprecedented repatriation to the South Asian nation.

The National Immigration Institute said in a statement late on Wednesday that it had flown the 310 men and one woman to New Dehli from Toluca.

The migrants had been detained by immigration officials in various Mexican states before being concentrated at a detention centre in the state of Veracruz in preparation for their deportation.

The vast majority of migrants transiting Mexico toward the US border are from Central America, but among the mix are people from all over the world.

Mexico has stepped up its immigration enforcement in recent months under pressure from the United States. The government has deployed thousands of National Guard agents along the major migration routes.