(Reuters) - Latham & Watkins, one of the world"s largest law firms, said Thursday it is canceling "further indoor holiday parties" in the wake of an apparent COVID-19 outbreak tied to a party its New York corporate department held last week. A spokesperson for the 3,000-lawyer firm said in an email that "a number of positive cases" "appear to relate" to the party. She declined to say how many people contracted the virus and said everyone in attendance was vaccinated. Latham mandated employee vaccinations in September. "While we very much want to reconnect and celebrate the season together, the most important thing to us, now and throughout the pandemic, is the safety of our colleagues and their families," Marc Jaffe, the managing partner of Latham"s New York office, said in a statement on the decision. The firm didn"t say how many people attended the Dec. 2 party but said attendance was voluntary. An internal Latham email published by the legal blog Above The Law said attendees should not return to the office unless they have tested negative at least five days afterward. Latham"s website lists more than 500 lawyers in its New York office. The firm in May said it expected all of its employees to be within "commuting distance" and to "have re-established their regular routine of working from the office" by mid-September. U.S. law firms have been bringing lawyers back to the office in fits and starts this year, with some delaying planned office returns during the rise of the Delta variant. Latham, whose New York office handles a high volume of financial services work, did not respond to a request for comment on its latest office safety or attendance policies. Earlier this week, investment bank Jefferies Financial Group asked staff to work from home again due to a spate of COVID-19 cases. The pandemic has also prompted several large banks to discontinue or scale down their holiday plans this year. Wells Fargo said there are no firm-wide holiday parties planned, but team parties are up to managers" discretion. JPMorgan Chase & Co. has canceled its annual festive carols reception in London and year-end party in Paris. A Latham spokesperson did not answer whether its new policy on holiday parties applies equally across its roughly 30 global offices.