Business owners are offering rides to work for employees living in the country illegally. Neighbors are buying groceries for people too nervous to go out and shop. Mothers are gently trying to tell their children they might have to be apart for a little while.

Reports that the US Immigration and Customs Enforcement agency is planning to launch nationwide raids over this weekend and arrest thousands of undocumented immigrants have sparked alarm and uncertainty in immigrant communities in Massachusetts, causing many to retreat to the shadows in fear.

“Nobody knows what to do,’’ said Yocelen, 22, who gave only her first name to avoid detection. She crossed the border a year ago after leaving Guatemala with her 5-year-old son and now lives in the Boston area.

“They don’t know if they can go out and even go shopping because they don’t know if [ICE] will grab you,’’ Yocelen said.

The operation is expected to take place over multiple days in at least 10 major cities, according to The New York Times, which first reported the planned raids.

Mayor Martin J. Walsh said Boston was not among the targeted cities, but immigrant advocates said no one knows what, exactly, to expect in Massachusetts. The administration has taken a hard line on illegal immigration and has vowed to step up deportations to discourage illegal immigration at the southwestern border. But last month, the administration threatened to carry out raids against undocumented families before agreeing to delay its plans at the last minute.

“The panic that’s out there is alarming,’’ said Gladys Ortiz, who works at REACH, a nonprofit that helps victims of domestic violence and works closely with immigrants and their families. Ortiz said her phone has been ringing constantly with calls from frightened immigrants, including a mother of five who called in tears, asking if she could find space for her family at a shelter for a few days.

“My head is like. ‘Oh my God,’ ’’ Ortiz said. Women “keep calling me and ask, ‘What am I going to do? What am I going to do?’ ’’

On Friday, President Trump told reporters the raids will focus on criminals but acknowledged that his administration would arrest anyone who came to the United States illegally.

The sweeps are meant to target immigrants facing deportation orders but will include “collateral’’ deportations of undocumented immigrants who are present during targeted arrests, according to The New York Times.

In East Boston, an “emergency community education session’’ is scheduled for Saturday at the public library on South Bremen Street. On Thursday, people packed the office of the consulate of El Salvador in East Boston, where representatives from countries such as Honduras, Peru, Columbia, and Mexico gathered to provide immigrants information about their rights.

About 250,000 unauthorized immigrants live in Massachusetts, according to a 2016 estimate by the Pew Research Center.

Walsh said city police would have no role in helping ICE detain immigrants. In Chelsea, which has a high concentration of immigrants, Police Chief Brian Kyes offered similar assurances.

“The enforcement of our nation’s civil immigration laws are the primary responsibility of the federal government,’’ Kyes said in a statement. “Accordingly, all Chelsea residents can be assured that the officers of the Chelsea Police Department shall not and will not undertake or become involved in any civil immigration-related investigations that do not have a direct nexus to criminal activity.’’

Around East Boston, residents in the largely immigrant neighborhood said they have been on high alert for days.

José Goméz, who owns a convenience store in East Boston, has offered to deliver goods from his store to fearful customers who have not left their homes in days. He has at least six employees who are unauthorized immigrants, and he has offered to drive them all into work so they can minimize the risk of arrest.

“It’s stressful,’’ Goméz said. “We have to try to help them.’’

Wilder Cerrate, 19, thought of his cousins as he stood outside the East Boston Social Centers where he had just picked up his sister from an after-school program.

Cerrate, who is in the country legally, said he is worried about what will happen to family members who are not.

“It’s just bracing yourself for impact,’’ Cerrate said.

People are “practicing their lines,’’ he said, by reminding themselves they do not have to answer their doors unless an ICE officer has a court order or warrant signed by a judge.

“We try to keep calm,’’ Cerrate said. “We try not to let it take over our whole lives. It’s a type of calm where you actively have anxiety in the back of your head.’’

Rosa, a 42-year-old Guatemalan woman who is living with her 20-year-old daughter, said she is trying to be pragmatic and maintain her regular life.

“We have to keep working,’’ said Rosa. “We have to make money to buy food, clothes, and shoes.’’

Rosa, who asked to be identified by just her first name, said her daughter is terrified of going to work this weekend at her job tending to the grounds of golf courses. Rosa, who cleans offices and houses for a living, advised her daughter to go to work.

“Ask God for help,’’ she said she told her. “Only God can protect us.’’

Yocelen, the young Guatemalan woman, said she won’t dare leave her apartment.

“I don’t even want to go out on the street for fear that [ICE] will take me away,’’ she said. She dreads returning to Guatemala, which she fled after drug dealers threatened her and came to her home because police told them she had reported their activities to the authorities.

“They’ll kill me,’’ Yocelen said. “They never forget anything.’’

Maria Cramer can be reached at mcramer@globe.com. Follow her on Twitter @GlobeMCramer.