KAMPALA, Uganda — A leading human rights activist from the Democratic Republic of Congo said on Friday that he had narrowly escaped what appeared to be an assassination attempt when gunmen infiltrated his home, took his children hostage and killed a security guard in a spray of bullets before fleeing in the family car.

On Thursday evening, four or five unidentified gunmen entered the home of the activist, Dr. Denis Mukwege, 57, while he was out, forced his two daughters and their friend onto the floor, confiscated their telephones and threatened to shoot them if they made any noise, according to a statement from Physicians for Human Rights, a humanitarian organization based in the United States, and a neighbor.Dr. Mukwege, one of Congo’s most high-profile personalities and a past Nobel Peace Prize nominee, said in a telephone interview on Friday that when he pulled up to the gate at his home in Bukavu, in eastern Congo, about an hour later, he saw “very strange people.” The gunmen forced their way into his car, and one stepped out and trained his gun on the doctor. Then one of his security guards appeared out of nowhere. The gunman menacing Dr. Mukwege whirled around and opened fire on the guard instead, Dr. Mukwege said, then fired at him. “They were shooting bullets in my direction,” he said. He scrambled to get away, and the assailants ran out of ammunition without hitting him. “And then they just jumped again in the car.”

The three children were also unharmed, but Dr. Mukwege’s security guard — Papa Djef, as he was known to the family — was killed. “He was like my child,” Dr. Mukwege said. “He was really a brave man. He just paid his life to save mine.”

Amnesty International called the attack a suspected assassination attempt, as did Physicians for Human Rights and Dr. Mukwege’s neighbor Christine Schuler Deschryver, the Congo director of V-Day, a group that fights sexual violence. Government agencies, including the Congolese Army and the local police force, could not be reached for comment on Friday. Dr. Mukwege said police officers had been sent to protect his house.