Here is what we know so far:

- Who was responsible? -

The plot was led by Christian Malanga, a 41-year-old Congolese man who was a "naturalised American", army spokesman General Sylvain Ekenge said late on Sunday.

The group was made up of "several nationalities", he said, adding that around 40 of the attackers had been arrested and four -- including Malanga -- killed.

"We also have a naturalised British subject, the number two of the group," the spokesman added.

Malanga's son, Marcel Malanga, was also among the attackers.

- Minister's residence attacked-

The events unfurled at around 4:00 am local time (0300 GMT) in the northern Gombe district of the capital that is home to a number of embassies and institutions.

Witnesses saw around 40 people in at least seven vehicles attack the home of Economy Minister Vital Kamerhe, armed with automatic weapons and in possession of drones.

The shooting at the minister's home lasted almost an hour before security forces arrived.

Kamerhe and his family were not injured in the violence, but two police officers guarding them were killed.

Two attackers were also killed, agents assigned to the minister's guard told AFP on site on Monday.

Several bullet holes were visible on the walls and on vehicles at Kamerhe's home, and windows were broken, AFP witnessed.

A minibus in which the attackers arrived was also abandoned in the street.

- Palais de la Nation-

The assailants then moved to the Palais de la Nation near Kamerhe's home which sits on the banks of the Congo River.

The historic building houses the offices of President Felix Tshisekedi but is empty at night and is protected by members of the Republican Guard.

Assailants "forced the barrier" of palace, according to a national media broadcast on Sunday evening.

According to the broadcast, other "attackers and mercenaries" were "pre-positioned in the swamps along the river".

- 'Long-live Zaire'-

When inside the Palais de la Nation the attackers filmed themselves brandishing a flag of Zaire, the name of the DRC during the time of Mobutu Sese Seko, the dictator overthrown in 1997.

The group's leader Malanga was filmed saying: "Long live Zaire, long live the children of Mobutu".

"Felix has fallen... We are victorious."

The assailants were stopped when security forces came to the palace, putting an end to the coup bid.