U.S. Customs and Border Protection officers have apprehended an additional 1,600 people attempting to illegally enter the country from Mexico since April 15 as a result of the deployment of National Guard troops to the southwest border, CBP and defense officials said Wednesday.

National Guard officials overseeing the border state deployments said troops helping monitor the international boundary have freed up more border agents to physically guard the border. The result has led to a surge in the amount of criminal activity agents have stopped.