Greece's government has condemned an attack on the Athens home of an Afghan refugee family whose son made news after being picked to carry the Greek flag at a school parade.

The windows of the family's apartment were broken by stones in Friday's pre-dawn attack, which government officials, political parties and the U.N. refugee agency denounced as racist.

The family's 11-year-old son had drawn the lot for the traditional honor of carrying the flag at a parade last week remembering the country's entry into World War II. The Education Ministry has ordered an investigation into why the boy ended up instead carrying a sign with the name of his primary school.

Racist attacks have increased during Greece's financial crisis, and a Nazi-inspired nationalist party entered parliament in 2012.