Los Angeles County is reporting 436 new cases of COVID-19 and two additional deaths, though health officials said the numbers likely reflect reporting delays over the holiday weekend.

Hospitalizations in the county due to COVID-19 dropped from 284 to 273, with the number of COVID patients in ICU units declining from 77 to 65, according to state figures.

Monday’s figures brought the county’s totals to 1,252,739 cases and 24,504 fatalities since the pandemic began, according to the Los Angeles County Department of Public Health.

The county’s rate of infections has grown alarmingly over the past several days. Health officials say the increase is being fueled by the rise in COVID-19 variants, particularly the more contagious Delta variant. They added that with 4 million residents in L.A. County still unvaccinated and a tripling of cases over the past week, there is enough risk for the variant to pose a significant threat.

The variant is believed to be responsible for more than 26 percent of current COVID infections in the United States, and is also blamed for rampant infections in India and parts of the United Kingdom.

It has also become California’s most identified strain of the coronavirus, accounting for 35.6 percent of the variants analyzed in June—a steep increase from May, when the number was just 5.6 percent, according to the California Department of Public Health.

“We are grateful to everyone for the tremendous progress we have made over the past year, yet we are not out of the woods just yet,’’ Los Angeles County Public Health Director Barbara Ferrer said over the weekend.

“If you are unvaccinated, consider getting your vaccination now to increase your protection as other public health precautions have been lifted; talk to a friend or loved one who has been vaccinated and ask them about their experience. Vaccines provide us with the best tool for ending this pandemic that has plagued us for so many months.’’

Meanwhile, the county’s Black residents saw their rates of infections and hospitalizations rise during a time when other ethnic groups were seeing lower numbers, according to the latest data from the health department. Over a two-week period in late May and early June, the case rate for Black residents rose 18 percent, but declined 6 percent for white residents, 4 percent for Latino residents and 25 percent for Asian Americans.

The hospitalization rate for Blacks grew by 11 percent while declining 37 percent for Whites, 12 percent for Asian Americans and 29 percent for Latinos.

Statistically, Black residents are less likely than other racial and ethnic groups in Los Angeles County to get vaccinated against the virus. In mid-June, county health officials expressed concern that young Black and Latino residents continue to lag behind the rest of the population in COVID-19 vaccination rates.

Among Black residents, only 15 percent of the population age 12-15 had received at least one dose of vaccine, and 21 percent of Latinos in that age group, compared to 38 percent of Whites. Among 16- to 17-year-olds, only 24 percent of Black residents have at least one dose and 37 percent of Latinos, compared to 54 percent of Whites.

Health officials have been closely watching case numbers and testing-positivity rates, which have been steadily inching upward since most COVID health restrictions were lifted on June 15. The increases come as a highly contagious “Delta’’ variant of the COVID-19 virus continues spreading locally and nationally.

Ferrer said Thursday 245 cases of the “Delta’’ variant have been confirmed in the county, nearly double the number from last week. The county conducts limited sequencing tests needed to identify the variants, so the number cannot be extrapolated across the population, but “Delta’’ has become the most dominant variant detected in the county.