KAMPALA, April 18 (Reuters) - A man was charged in a Ugandan court on Thursday with kidnapping for ransom an American tourist and her driver earlier this month, police said.

Kimberley Sue Endecott, 35, and local guide Jean Paul Mirenge-Remezo were ambushed and seized by gunmen as they drove in Queen Elizabeth National Park in southwest Uganda on April 2.

The kidnappers demanded a ransom of $500,000 and the pair were released six days later.

Onesmus Byaruhanga, who appeared in court to be charged, "played a supportive role of surveilling the movement of the American tourist," police said in a statement.

Byaruhanga, the police said, has a history of carrying out kidnappings and robberies in the area and provided crucial "information that facilitated the kidnapping of the two" and he was also involved in pressing ransom demands.

The firm that organized Endecott's safari has said she and her guide were released after a "negotiated settlement" and a Ugandan official also said a ransom was paid.

Queen Elizabeth National Park, where the victims were seized, is one of Uganda's most visited, with visitors flocking there to see lions, zebras, hippos, elephants and other attractions.

Kidnappings and other forms of assault on tourists are rare in the East African country.

The last major similar incident occurred in 1999 in Bwindi Impenetrable Forest near the border with Democratic Republic of Congo, when an American couple, four Britons and two New Zealanders were killed along with four guides after being ambushed by gunmen. (Reporting by Elias Biryabarema; Editing by Hugh Lawson)