At least one arsonist set two gay pride flags on fire in front of a Harlem bar just before the start of Pride Month, police said — an act Gov. Cuomo condemned.

Cops were called at around 12:20 a.m. Friday to Alibi Lounge on West 139th Street near Adam Clayton Powell Jr. Blvd., where two rainbow flags were set ablaze, police said Saturday. By the time officers arrived the flames were extinguished by the rain, and no one was hurt.

The arsonist remained at large, and cops are investigating the crime as a possible bias incident.

“Some a–hole set our rainbow flags on fire!” the bar tweeted. “It’s a hate crime!”

Cuomo blasted the brazen act.

“I am disgusted by the burning of a Pride flag outside an LGBTQ bar in Harlem early yesterday morning,” the governor said in a Saturday tweet.

“There is no place for hate in New York. Rather than divide New Yorkers, this despicable act will only strengthen our commitment to tolerance, equality and justice for every individual,” he added.

Patrons agreed with Cuomo.

“Why do people have to do these things? Can’t we just get along with each other instead of burning each other’s flags?” lamented Vincent DePaula, of the Upper East Side.

The flags were intended to celebrate Pride Month — which culminates June 30 with the WorldPride event celebrating the 50th anniversary of the Stonewall Uprising.

Meanwhile, Rhode Island Bishop Thomas Tobin urged the faithful to shun Pride Month celebrations.

“A reminder that Catholics should not support or attend LGBTQ ‘Pride Month’ events held in June,” he tweeted Saturday.

“They promote a culture and encourage activities that are contrary to Catholic faith and morals. They are especially harmful for children.”

But another Catholic priest, New York Jesuit James Martin, who has called for love and compassion for gay people, shared a completely different perspective.

“To all my many #LGBTQ friends, Catholic and otherwise: Happy #PrideMonth,” he tweeted. “Be proud of your God-given dignity, of the gifts God has given you, of your place in the world, and of your many contributions to the church. For you are ‘wonderfully made’ by God (Ps 139). #PrideMonth2019.”

Additional reporting by Nick ­Fugallo