Brushing aside protests from immigrant advocates and both Democratic presidential candidates, the Obama administration is moving ahead with a surge of deportations in the coming weeks, aimed mainly at mothers and children from Central America, immigration officials said Friday.

The Department of Homeland Security is stepping up the pace of deportations to send a tough enforcement message to Central America and to try to head off a seasonal swell of illegal crossings of the southwest border, the officials said. Those crossings generally rise during the summer, and administration officials are especially concerned because there was an unexpected increase in the numbers of migrants last fall.

The new plans do not include intensive raids like those over one weekend in January, when about 120 women and children were detained for deportation in Georgia, North Carolina and Texas, the officials said. Instead, immigration agents will speed up the arrests of individual families, which they have been making nationwide since the January raids.

Marsha Catron, a spokeswoman for the department, said those operations focus on migrants who were caught at the border after Jan. 1, 2014, denied asylum by immigration courts, and ordered deported by judges. Agents also will arrest migrants who came when they were minors but turned 18 while fighting deportation in the courts, making them ineligible for protections as children.