Children dropped off at the Cayuga Center in East Harlem.

Children are led into the Cayuga Center facility in Manhattan.

Kids of many ages — including some wearing masks to cover their faces — came in droves to foster care facilities in Harlem on Thursday morning, a day after Mayor Bill de Blasio said hundreds were being housed at the centers under President Trump’s “zero tolerance” immigration policy.

Dozens of children ranging in age from about 5 to 11 were paraded into Cayuga Center facilities on West 125th Street near Broadway and at East 131st Street and Park Avenue starting as early as 7:15 a.m.

Many toted new backpacks and either wore masks or held their hands up to their faces to shield themselves from the media as they entered the buildings. At least two babies were carried in by adults.

Some of the kids were dropped off by SUVs — though it’s unclear where exactly they were coming from or whether they were indeed migrants.

NYPD cops stood guard outside the facilities.

More than 350 migrant children have been sent to Cayuga after being separated from their parents at the Mexican border under Trump’s policy, de Blasio said Wednesday.

De Blasio toured the 131st Street center and said workers told him the youngest child brought there was 9 months old.

The children arrive at the agency for school during the day and live at foster homes at night, the mayor said.

A federal source told The Post that another 300 kids were due to arrive in New York City in the coming weeks.