President Donald Trump again claimed Friday night that Puerto Rico’s official Hurricane Maria death toll is incorrect, criticizing a public health school report estimating the number at nearly 3,000.

Trump first attacked the research Thursday morning, falsely claiming that the data was “done by the Democrats” to “make me look as bad as possible.” A team of researchers from the Milken Institute School of Public Health released the estimate last month after reviewing six months of death certificates and using a mathematical model to compare deaths in the months after the hurricane to the mortalities during a typical year.

“They hired GWU Research to tell them how many people had died in Puerto Rico (how would they not know this?)” Trump tweeted Friday. “This method was never done with previous hurricanes because other jurisdictions know how many people were killed. FIFTY TIMES LAST ORIGINAL NUMBER – NO WAY!”

“When Trump visited the island territory last October, OFFICIALS told him in a briefing 16 PEOPLE had died from Maria.” The Washington Post. This was long AFTER the hurricane took place. Over many months it went to 64 PEOPLE. Then, like magic, “3000 PEOPLE KILLED.” They hired….

— Donald J. Trump (@realDonaldTrump) September 15, 2018

….GWU Research to tell them how many people had died in Puerto Rico (how would they not know this?). This method was never done with previous hurricanes because other jurisdictions know how many people were killed. FIFTY TIMES LAST ORIGINAL NUMBER – NO WAY!

— Donald J. Trump (@realDonaldTrump) September 15, 2018

The Puerto Rican government, which commissioned the study in February, raised its official death toll from 64 to 2,975 after the study was released.

Milken researchers stood by their research Thursday in a statement, saying the approximated 3,000 deaths are “the most accurate and unbiased estimate of excess mortality to date.”