"The push alert system for our mobile app was compromised this evening. Please accept our apologies," the newspaper said on Twitter several hours after the alerts went out.
The tabloid newspaper did not provide details of the alerts from its app, but screen grabs posted online by Twitter users included an alert reading "Heil President Donald Trump!" among a series that ran on Saturday, which was April Fool's Day.
Other posts were more cryptic, vague or seemingly religious in nature, with the final one reading "with Lucid Love, Selah," according to media reports and screen shots posted on Twitter.
The Post is owned by News Corp.
(Reporting by Chris Michaud, Editing by Kim Coghill)
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)