Workers who picketed 19 major Southern California hotels over the long holiday weekend were back on the job Wednesday, but their union warned that more walkouts could come at any time.

No progress was reported in negotiations between employers and Unite Here Local 11, which represents bellhops, front desk agents, room attendants, cooks, servers and dishwashers.

Union members voted last month to strike at 60 hotels in Los Angeles and Orange counties. They are demanding better wages, improved health care benefits, higher pension contributions and less strenuous workloads.

The soaring cost of living in greater Los Angeles is a significant problem for hotel workers, according to the union.

Unite Here Local 11 spokeswoman Maria Hernandez described this week’s walkouts as the “first wave” in an ongoing labor action that could soon bring picket lines to 41 other hotels.

“We went on strike to show these companies what we were willing to do to win a fair contract,” said Joy Johnson, a housekeeper at the Courtyard Marriott Downtown LA.

Contracts expired last Friday at hotels owned by major chains including Hilton and Fairmont. The strike affects about half of the 32,000 hospitality workers the union represents across Southern California and Arizona.

Last week, a deal was reached with its biggest employer, the Westin Bonaventure Hotel & Suites in downtown Los Angeles, which has more than 600 union workers. Union officials described the tentative agreement, which provides higher pay and increased staffing levels, as a major win for workers.

Talks with other hotels — including the Ritz-Carlton, Four Seasons Regent Beverly Wilshire and Anaheim Hilton, near Disneyland — were at a stalemate. A coalition of more than 40 hotels involved in talks on Monday accused union leaders of canceling a scheduled bargaining session and refusing to come to the table. The hotels have offered wage increases of $2.50 per hour in the first 12 months and $6.25 over four years, the group said.

The walkout came amid holiday celebrations and a major anime convention in Los Angeles. Temporary employees were hired to cover for the striking workers, and it wasn’t immediately clear whether the strike resulted in guests checking out early or lacking services.