Three Americans were among about 50 assailants arrested in the Democratic Republic of Congo on Sunday during a failed coup that included an attack at the presidential palace, the African nation’s army said.

The coup attempt led by self-exiled opposition leader Christian Malanga began around 4 a.m. as gunfire rang out in the capital, Kinshasa, Reuters reported.

But it was “nipped in the bud,” and Malanga was killed at the presidential palace, Congolese army spokesperson Brig. Gen. Sylvain Ekenge said.

Malanga’s son was one of the three US citizens arrested following the attack, Ekenge told the Associated Press.

Those who were captured were facing interrogation by specialized services of the country’s armed forces, Ekenge, also told Reuters.

Social media videos show one of the Americans, a white man with blood around his mouth, sitting on the ground, appearing to beg his Congolese soldiers to spare him.

“I am shocked by the events of this morning and very concerned by reports of American citizens allegedly involved,” US Ambassador to the Congo Lucy Tamlyn said in a social media post.

“Please be assured that we will cooperate with the DRC authorities to the fullest extent as they investigate these criminal acts and hold accountable any US citizen involved in criminal acts.”

The chaos comes months after President Felix Tshisekedi was re-elected to a second term in a disorderly vote that critics claimed lacked transparency.

Tshisekedi has yet to name a government after he appointed a prime minister six weeks ago. He also delayed a vote for the parliament’s leadership that was originally scheduled for Saturday.

The attack began outside the home of a federal legislator who is running for speaker of the National Assembly of Congo.

Lawmaker Vital Kamerhe’s guards were able to fight off the armed men during the exchange of gunfire in which two police officers and one of the attackers were killed, a spokesperson for the lawmaker said.

Less than two miles from Kamerhe’s home, Malanga, the opposition leader, was killed at the presidential palace after he resisted arrest by guards, the nation’s army said.

Before he was killed, he appeared in a livestream video at the palace around several other people wearing military uniforms.

“Felix, you’re out,” he said in the video. “We are coming for you.”

The UN’s stabilization mission in the Congo said in a social media post that its chief, Bintou Keita, strongly condemned the failed coup and offered any support Congolese officials need.

With Post wires