Police in Sierra Leone are on the hunt for a group of chimpanzees, who escaped from their wildlife sanctuary after a fatal attack on construction workers.
Police said Bruno had instigated the attack
Armed reinforcements are combing the area after a Sierra Leonean died and four people were seriously injured.
Security personnel said the five men were attacked on Sunday after entering the Tacugama Chimpanzee Sanctuary.
Angry chimps killed and mutilated the driver. Three North Americans are in a hospital in the capital, Freetown.
Another Sierra Leonean was also badly injured - and reportedly needed to have his hand amputated.
A worker at Tacugama told the BBC that some 24 chimpanzees had escaped, while six had already returned.
The violent attack was instigated by Bruno, the first chimpanzee taken in by the sanctuary and its alpha-male, along with two other primates, police said.
Armed police arrived after the attack and fired shots which caused panic among local people.
Tourism Minister Okere Adams visited the scene just outside Freetown and said police were searching the area to find the chimps and bring them back to the sanctuary.
"We are combing the area and beyond to bring the chimpanzees back but would not harm them," a police officer told AFP news agency.
The authorities have warned residents of the mountain villages around the sanctuary not to approach any chimpanzees they come across.
The sanctuary was set up a decade ago to give shelter to orphaned and abandoned chimpanzees.
Across West Africa, chimpanzees are under threat from hunting, logging and human encroachment.