(Reuters) – Americans should avoid door-to-door trick-or-treating, attending crowded and indoor parties, and wearing costume masks this Halloween to prevent the spread of COVID-19, according to the U.S. Centers for Disease Control and Prevention.

The U.S. health agency said that many traditional Halloween activities could be high-risk for spreading viruses and outlined several safer, alternative ways to participate in a note on holiday celebrations.

The guidance comes after new COVID-19 cases in the United States rose last week for the first time after falling for eight straight weeks, an increase that health experts attributed to schools reopening and parties over the Labor Day holiday.

The health agency also said activities like attending haunted house settings, consuming alcohol or drugs and attending the fall festival that is outside one’s community were high risk and should be avoided.

CDC advised one-way trick-or-treating where participants are six feet apart and wearing Halloween-themed cloth masks.

Other low-risk activities include carving pumpkins and decorating one’s home, outdoor scavenger hunts and parties, virtual costume contests and hosting a movie night with household members.

The health agency recommended tailoring all Halloween activities based on whether coronavirus infections were spiking in a given area, adding that the new guidelines are not meant to replace any local or state mandates on the pandemic.

For Thanksgiving, CDC advised against long distance travel, attending crowded parades and going shopping in crowded shops.

(Reporting By Mrinalika Roy in Bengaluru; Editing by Shailesh Kuber)