American citizens appear to be among a group detained in the Democratic Republic of the Congo for their alleged involvement in a failed coup attempt, authorities in the African nation said Sunday.

The arrests were made after a deadly shootout near a government official’s home in the capital Kinshasa, which killed three people. Congolese army spokesperson Brig. Gen. Sylvain Ekenge said the coup, which was enacted by both Congolese and foreigners, had been quickly thwarted by national security forces.

The U.S. ambassador to the country, Lucy Tamlyn, said on X that she had been informed of the alleged involvement of American citizens and said the embassy was cooperating with the Congolese government.

“I am shocked by the events of this morning and very concerned by reports of American citizens allegedly involved,” she wrote in French. “We will cooperate with DRC authorities to the fullest extent as they investigate these criminal acts and hold accountable any U.S. citizen involved.”

Footage of two men under arrest quickly made the rounds on social media. One of the men in the video was identified as the American son of the coup’s Congolese ringleader, Christian Malanga. Also in circulation were pictures of a U.S. passport apparently belonging to Benjamin Zalman-Polun, a 36-year-old born in Maryland. Zalman-Polun is reportedly a cannabis entrepreneur who has been linked to the suspected leader Malanga. Malanga is the founder of a political organization for Congolese people in the U.S., and he posted a livestream Sunday afternoon that appeared to show him leading the charge.

The coup reportedly began around 4:30 a.m. Sunday morning near the residence of Vital Kamerhe, who is running to be speaker of the national legislature. The attackers were met with gunfire, an exchange that killed a coup member and two police officers, a spokesman for Kamerhe wrote on X.

The attackers then moved on to the presidential palace, Congolese media said, which is just a mile away. But they were arrested by security forces there, and the coup was shut down. Ekenge, the Congolese army spokesman, told the Associated Press that the likely ringleader Malanga had been killed during the clash.

The target of the coup was believed to be President Felix Tshisekedi, who won a second term in a chaotic December vote. Tshisekedi was unharmed, and multiple U.S. news outlets characterized the plot as a poorly organized scheme that relied on amateur tactics.