BRUSSELS, Belgium -- Belgian Foreign Minister Didier Reynders has come under criticism for appearing with a blackened face at a charity event, raising questions about Belgium's sensitivity toward racism.

Reynders insisted he blackened his face only as part of a century-old Belgian tradition aimed at raising money for the poor. But human rights groups were outraged Thursday by his action over the weekend.

"This man presents an image of our nation abroad," said Wouter Van Bellingen, head of the Minorities Forum. "This in unacceptable."

Reynders posted a picture of himself blackened up on his website, and said on his Facebook page that he likes "being part of folklore at Carnival time ... as tradition wants it."

He was referring to a late 19th century Brussels tradition in the early days of colonialism when people dressed up and blackened their faces to be anonymous as they collected money for poor kids.

Belgium has also been criticized for using a character called "Black Pete" -- seen by many as a grotesque black stereotype -- as Saint Nicolas's helper. The Black Pete controversy has been strongest in the Netherlands, where it is also a pre-Christmas tradition, but closely followed in Belgium too.

"That was quite a shock to see a foreign minister do that," said Andrew Stroehlein of Human Rights Watch. "Do we want this to be the face we present to the outside world?"

Across Belgium and the Netherlands, celebrations in which Saint Nicholas rolls into town surrounded by a host of "Black Petes" have come under increasing pressure and triggered racism complaints year after year. Pete is usually played by a white person who paints his face pitch black, dons a frizzy wig and gives himself bright red lips -- stereotypes that disappeared from most countries decades ago.

Even though the tradition of the charity is different, the look of Reynders with a black face, funny hat and frizzy white collar was reminiscent of Black Pete's looks.

Belgium is often watched with an eagle eye when it comes to such issues since it is the former colonizer of Congo, Rwanda and Burundi in central Africa.

"It shows a total disregard and lack of empathy for the situation," said Van Bellingen.