The Philippines has reported 227 more deaths from COVID-19, the highest figure in a day, but notes more than half of them had occurred as early as April.
The deaths were only reported or confirmed by local government units and added into the national tally now, the Department of Health said.
The latest figures bring the total death toll in the country to 1599.
The department also reported 2960 additional infections, pushing the national caseload to 57,006 as of Monday.
Health undersecretary Maria Rosario Vergeire said 167 of the deaths occurred in April, May and June, while 60 happened so far this month.
"We expect more deaths to be reported in the coming days as a result of our data reconciliation efforts," she told a televised media conference. "Should we be worried? Yes, because one too many deaths is a concern."
But Vergeire noted the number of deaths and cases was increasing because more complete data were being transmitted faster by local government units which had better access to information on the ground.
She urged the public to continue wearing face masks, observe physical distancing and frequent washing of hands to help stop further infections.
Several hospitals in the capital of Manila have announced their COVID-19 wards have been at full capacity since last week.
Makati Medical Center, one of the top hospitals in Manila, said it has attended to tens of thousands of patients suspected of being infected with coronavirus since February and was unable to accept more cases.
"Much as we would want to extend the same degree of care and attention to any additional admission for COVID-19, Makati Medical Center has reached its threshold in its capacity to respond to more COVID-19 patients," it said in a statement.
St Luke's Medical Center, another top hospital in Manila, said its two branches could also no longer take in more patients but would announce it if could re-open admissions for coronavirus cases.
"We appeal to the public to avoid complacency and strictly adhere to health protocols and preventive measures against COVID-19," it said in a statement on Monday.
Since June 1, the Philippines government has been easing the lockdown, imposed on the country's most populous island of Luzon, which encompasses Manila, and in other high-risk areas in mid-March.
Limited public transportation has resumed, while shopping malls, salons, barber shops, restaurants, private offices and even some churches have also opened in a reduced capacity.
Australian Associated Press