Explosive drones targeting a suspected gang leader killed at least eight children inside a slum in Haiti’s capital and seriously wounded six others, relatives and activists told The Associated Press on Monday, as they blamed police for the attack.

The explosions happened Saturday night in Cité Soleil, which is controlled by Viv Ansanm, a powerful gang coalition that the U.S. has designated as a foreign terrorist organization.

One of its leaders, Jimmy Chérizier, best known as Barbecue, vowed to avenge the attacks, with a total of at least 13 people killed, according to residents.

Michelin Florville, 60, said the explosion killed two of his grandchildren, ages 3 and 7, and his 32-year-old son.

“People were running right and left,” he recalled, noting that he was standing near where one explosion occurred.

Haiti’s National Human Rights Defense Network accused police of launching two kamikaze drones in the Simon Pelé community of Cité Soleil as suspected gang leader Albert Steevenson, known as Djouma, prepared to celebrate his birthday.

The group said that Steevenson was distributing gifts to children when the attack occurred.

Romain Le Cour, head of Haiti Observatory at the Global Initiative Against Transnational Organized Crime, said the attack raises “urgent questions of accountability.”

AP Video shot by Pierre Luxama