Two mountain gorillas have been born in the Democratic Republic of Congo's famous Virunga National Park, bringing to nine the number of babies born this year, the park has said in a tweet.

A 19-year-old mountain gorilla named Kayenga gave birth to her third child, a boy, while eight-year-old Anangana gave birth to her first baby, a girl, the park said in a statement.

The mountain gorilla is one of the world's most endangered animals.

"Over the last decade, Virunga National Park’s mountain gorilla families have played a major role in increasing the worldwide population, which now stands at over 1,000," the park said.

"This is a significant jump from the 790 individuals recorded in 2010 and it is fantastic to see this magnificent, yet highly endangered species, continue to thrive," it added.