NEW YORK — Fast-food workers and labor organizers marched, waved signs and chanted in cities across the country on Thursday in a push for higher wages.

Organizers say employees planned to forgo work in 100 cities, with rallies set for another 100 cities. But by late afternoon, it was unclear what the actual turnout was or how many of the participants were workers. At targeted restaurants, the disruptions seemed minimal or temporary.

The protests are part of an effort that began about a year ago and is spearheaded by the Service Employees International Union, which has spent millions to bankroll local worker groups and organize publicity for the demonstrations. Protesters are calling for pay of $15 an hour, but the figure is seen more as a rallying point than a near-term possibility.

At a time when there’s growing national and international attention on economic disparities, advocacy groups and Democrats are hoping to build public support to raise the federal minimum wage of $7.25. That comes to about $15,000 a year for full-time work.

On Thursday, crowds gathered outside restaurants in cities including Boston, Lakewood, Calif., Phoenix, Washington, D.C., and Charlotte, N.C., where protesters walked into a Burger King but didn’t stop customers from getting their food.

In Detroit, about 50 demonstrators turned out for a pre-dawn rally in front of a McDonald’s. A few employees said they weren’t working but a manager and other employees kept the restaurant open.

Julius Waters, a 29-year-old McDonald’s maintenance worker who was among the protesters, said it’s hard making ends meet on his wage of $7.40 an hour.

“I need a better wage for myself, because, right now, I’m relying on aid, and $7.40 is not able to help me maintain taking care of my son. I’m a single parent,” Waters said.

In New York City, about 100 protesters blew whistles and beat drums while marching into a McDonald’s at around 6:30 a.m.; one startled customer grabbed his food and fled as they flooded the restaurant, while another didn’t look up from eating and reading amid their chants of “We can’t survive on $7.25!”

Community leaders took turns giving speeches for about 15 minutes until police arrived and ordered protesters out of the store. The crowd continued to demonstrate outside for about 45 minutes.

Later in the day, about 50 protesters rallied outside a Wendy’s in Brooklyn. Channon Wetstone, a 44-year-old attorney ended up going to a nearby Burger King because of the protests.

She said that fast-food employees work very hard. When asked if she’d be willing to pay more for food so they could earn more, she said it would depend on what she was ordering.

“I would say 50 cents, 75 cents more,” Wetstone said.

The push for higher pay in fast food faces an uphill battle. The industry competes aggressively on being able to offer low-cost meals and companies have warned that they would need to raise prices if wages were hiked.

Fast-food workers have also historically been seen as difficult to unionize, given the industry’s high turnover rates. But the Service Employees International Union, which represents more than 2 million workers in health care, janitorial and other industries, has helped put their wages in the spotlight.

Berlin Rosen, a political consulting and public relations firm based in New York City, is coordinating communications efforts and connecting organizers with media outlets. The firm says its clients are the coalitions in each city, such as Fast Food Forward and Fight for 15. Those groups were established with the help of the SEIU, which is also listed on Berlin Rosen’s website as a client.

The National Restaurant Association, an industry lobbying group, said most protesters were union workers and that “relatively few” restaurant employees have participated in past actions. It called the demonstrations a “campaign engineered by national labor groups.”

McDonald’s, Wendy’s and Yum Brands, which owns KFC, Taco Bell and Pizza Hut, said in statements that their restaurants create work opportunities and provide training and the ability to advance. Burger King reissued its statement on past protests, saying its restaurants have provided an entry point into the workforce for millions of Americans.