Colombia will deport 33 Venezuelans in the country illegally amid warnings that the recent reopening of the two nations' border could be fueling a wave of illegal immigration.

Migration officials said Monday the 33 Venezuelan women were detained in the northern city of Barrancabermeja and would be taken to the border for expulsion soon.

Venezuelans desperate to buy food and medicine hard to find at home have been flooding across the border since Venezuelan President Nicolas Maduro this month reopened crossings that he closed a year earlier as part of a crackdown on smuggling.

Over the weekend, Colombian President Juan Manuel Santos welcomed the reopening but warned that some Colombian cities have been experiencing "invasions" by Venezuelans who have refused to return home amid Venezuela's worsening economic crisis.