A six-year-old died on Monday after being mauled by a caged lioness in a resort in the southern Gaza Strip, officials in the Palestinian territory said.

The boy climbed a protective fence at the Asda resort in Khan Yunis and reached the animal's cage, police said, resulting in his injury and death.

Eyewitnesses said the boy had squeezed his way through a small hole in the fence and approached the cage, upon which the lioness bit his head, with security forces pulling him away as he bled.

A medical source said the child was taken to a hospital in the city, where he died.

Police said they launched an investigation into the incident and closed the resort, which has another lion as well as a number of birds.

Khan Yunis gained notoriety for hosting what animal welfare charity Four Paws called the "world's worst" zoo.

It opened in 2007 and eventually shut down in 2016 after owners struggled to afford food and many of the animals starved to death.

Some 2.3 million Palestinians live in the Gaza Strip, which has been under a crippling Israeli-led blockade since Islamist group Hamas rose to power in 2007.

Israel and militant groups in Gaza have fought several wars over the past 15 years. (AFP)