The Netherlands said Thursday it will hand back hundreds of colonial-era artifacts to Indonesia and Sri Lanka, including a haul of treasure and a gem-encrusted bronze cannon.

The decision to return some 478 objects followed recommendations by a government-appointed commission last year looking into illegal Dutch colonial acquisitions now being displayed in museums in the Netherlands.

"These recommendations are a milestone in dealing with collections from a colonial context," said Gunay Uslu, Dutch deputy minister for culture, education and science.

The commission was set up after a request by Indonesia for the return of some art pieces and natural history collections by its former colonial ruler the Netherlands.

Some of the items to be handed back include the so-called "Lombok treasure" of hundreds of golden and silver objects, looted by the Dutch colonial army after capturing the Cakranegara palace on Indonesia's Lombok island in 1894.

It also included a bronze cannon decorated with silver, gold and precious gems including rubies.

The 18th-century "Lewke's cannon" is believed to have been a gift by a Sri Lankan aristocrat called Lewke Disava to the king of Kandy around 1745-46.

It is believed to have fallen into Dutch hands in 1765 when Dutch troops led by the governor of Ceylon Lubbert Jan van Eck attacked and conquered Kandy.

After being displayed around the Netherlands, the cannon was eventually added to the Rijksmuseum's collection in Amsterdam.

Rijksmuseum director Taco Dibbits said the "restitution as a positive step in cooperation with Sri Lanka."

"The relationship and exchanges of knowledge built up between the two nations in the fields of research and common history constitute a strong foundation for the future," he added in a statement.

The commission will hand down decisions about other artifacts in the future, public broadcaster NOS said.

This included art from Nigeria as well as the Dubois collection which included the horse-riding reins of Prince Diponegoro, a Javanese royal who opposed Dutch colonial rule in the 19th century.

The Netherlands has been wrestling with the legacy of its colonial past in recent years.

Dutch King Willem-Alexander on Saturday issued a historic royal apology for the Netherlands' involvement in colonial-era slavery. (AFP)