The governments of El Salvador and Guatemala told Central American immigrants living in the United States to keep their doors closed to strangers -- the individual ringing the bell could be trying to detain and deport undocumented members of their families, they said. The warnings came amid a push by U.S. immigration officials to ramp up deportations and discourage the recently increasing number of unaccompanied children illegally crossing the U.S. border from Mexico.

“Don’t be fooled. Don’t open the door to unknown people who say they are looking for someone else,” the Guatemalan Foreign Ministry warned, according to a report by Fusion. The ministry released a five-point communiqué about the regulations and responsibilities of Immigration and Customs Enforcement agents.

“Immigration agents have to show an order signed by a judge to enter your house,” the communiqué stated, according to Fusion’s translation from Spanish. “If they don’t have one, you’re not obliged to open your door. You have rights that must be respected.”

El Salvador’s government posted on Twitter a series of tips to more than two million expatriates living in the U.S. The country’s message has similar wording to Guatemala’s warning.

The Department of Homeland Security confirmed on Monday that it had “engaged in concerted, nationwide enforcement operations” to return undocumented immigrants to their home countries. The operation resulted in 121 arrests in Georgia, Texas and North Carolina, among other states. The priority had been adults who entered the country illegally with children, the federal agency said in a statement.

Specifically, last weekend’s operations targeted adults and their children, many of whom were caught by Border Patrol agents after crossing the southern border illegally. Those targeted also should have received a deportation order from an immigration court and have no outstanding appeal, claim for asylum or request for humanitarian relief, according to the agency.

“As I have said repeatedly, our borders are not open to illegal migration,” Homeland Security Secretary Jeh Johnson said the statement. “If you come here illegally, we will send you back consistent with our laws and values,”

Mass deportation by the U.S. had some Central American governments on edge, Fusion reported. Sources at Homeland Security recently told the Washington Post that immigration officials planned to deport hundreds of undocumented immigrant families who have entered the U.S. since 2014.

Johnson said on Monday that the number of migrants apprehended at the border in 2015 had fallen by 30 percent to 331,333 -- the lowest number at the southern border since 1972. That’s compared to 486,000 apprehensions in 2014. However, the number of unaccompanied minors caught at the border had doubled through last October to 5,000, according to Border Patrol officials.

“I know there are many who loudly condemn our enforcement efforts as far too harsh, while there will be others who say these actions don’t go far enough,” Johnson said in the statement released Monday. “I also recognize the reality of the pain that deportations do in fact cause,” he added. “At all times, we endeavor to do this consistent with American values, and basic principles of decency, fairness, and humanity. ”