Police in Belgium deployed tear gas and water cannons on thousands of people who gathered in a Brussels park for an April Fools’ party, which was jokingly advertised as a Daft Punk reunion concert.

Some 20,000 accepted a social media invite for the party, and up to 5,000 revelers actually showed up for the foolish party — even though the event planners had said the invitation was a hoax.

Hundreds of cops used riot tactics to disperse the crowd as many partiers pumped their fists and chanted “freedom,” and threw bottles and rocks at police equipment.

“We are all depressed. I’ll be 18 in two weeks, we want to take advantage of our youth,” high school student Amelie said. “We came not to annoy the police, but to show that we also have a life and want to enjoy it.”

At least five people were injured, including three cops and a woman who was knocked down by a police horse. Four arrests were made, police said.

Belgium has limited outdoor gathering to groups of four people in its latest lockdown, which began last week following a March spike in coronavirus infections.

With Post wires