Later, an 8 p.m. to 6 a.m. curfew was announced by Kakudji as having being ordered by Kabila himself.
Kakudji also put all fighting units in Kinshasa on alert until further notice.
In the neighboring Republic of Congo, a senior military official said it was unclear who was in control of the Kinshasa government. The official declined to be named.
Hours after the apparent coup began, truckloads of armed soldiers patrolled the streets of the capital. Kinshasa residents hurried home, and many streets were quickly deserted.
Large numbers of troops in armored vehicles and on foot blocked off roads near Kabila's hilltop residence, not far from downtown Kinshasa. The presidential residence, known as the Marble Palace, is usually heavily guarded by troops and a North Korean-made tank.
Earlier today, a source familiar with the situation told ABCNEWS that based on current information, the 400 Americans living in Congo were not in danger. The capital was described as calm after the shooting, but it could become dangerous if the military unravels, and looting and civil unrest begins.
Americans have been told to stay to home. Of the Americans there, 200 of those are children, and 60 work for the embassy.
A Turbulent History
The Congolese president has been fighting a civil war since August 1998, when rebel forces backed by Kabila's former allies, Rwanda and Uganda, turned against him. In the war's early stages, the rebels reached the outskirts of Kinshasa before being turned back by Kabila's army, which is now supported by Angola, Namibia and Zimbabwe.
Kabila came to power in May 1997 following a Uganda- and Rwanda-sponsored rebellion against dictator Mobutu Sese Seko, who ruled the nation then called Zaire.
The international community initially welcomed Kabila, who many hoped would be a vast improvement over Mobutu's decades-long rule, which left his nation desperately broke and with an infrastructure that barely functioned.
But Kabila quickly alienated himself, inviting close friends and relatives into the government, angering investors and obstructing a U.N. investigation of reports that his rebel army had slaughtered thousands of Hutu refugees.
Kabila's government signed a peace agreement last year with the rebel movements, though fighting has continued and each side has consistently accused the other of violations.
The Associated Press and Reuters contributed to this report.