Three park rangers were killed by elephant poachers on Saturday during a shootout in the Democratic Republic of Congo.
The park's manager and another ranger also sustained gunshot wounds during the exchange at Garamba National Park - a UNESCO world heritage site.
Richard Sungudikpio Ndingba, Rigobert Anigobe Bagale, and Dieudonné Tsago Matikuli all died following the gun fight, the park announced.
Park Manager Erik Mararv and ranger Dieudonné Kanisa Adrupiako remain in stable conditions after sustaining gunshot wounds.
“We are devastated by this latest loss", said Peter Fearnhead, CEO of African Parks.
"Rangers put their lives on the line each and every day, and are under real siege in Garamba protecting elephants from heavily incentivised and militarized poaching gangs who threaten the very survival of humans and wildlife alike".
In 2015, Garamba lost five guards and three members of the Congolese Armed Forces who were killed by heavily-armed elephant poachers in three separate incidents.