(CNN) - Nigerian authorities specified Friday that a total of 276 schoolgirls were taken last month by militants from a boarding school, but 53 of them escaped, leaving 223 still in the hands of their captors, police said.
Those numbers are higher than previously reported. Authorities had been saying about 230 girls were abducted in the dead of night at a high school in the country's northeast region - a hotbed for the Islamist group Boko Haram - and roughly 200 of the girls were missing.
Authorities quickly added Friday that the new figure for missing girls - 223 - could grow as police fill in spotty school enrollment records.
At a minimum, Friday's announcement provided a clearer picture of how many girls are still missing.
"After thorough investigation by the police and other security agencies we have been able to compile a list of 276 girls initially abducted from the school," said Lawan Tanko, the Borno state police commissioner.
"Out of this number 53 were able to escape while 223 are still being held by the kidnappers," Tanko said. "This list may not be exhaustive because there could be other missing girls excluded because their parents may not have registered their names, which is why we have made announcement calling on parents whose girls were missing at the school to come forward and submit the name of their missing children."