Three German men were arrested at the weekend when they flew home from Kenya, accused of having joined and fought with Somalia’s Shebab militant group, officials said Monday.

Three German men were arrested at the weekend when they flew home from Kenya, accused of having joined and fought with Somalia's Shebab militant group, officials said Monday.

They were arrested on terrorism charges Saturday at Frankfurt airport and the following day brought before a judge who ordered them placed in pre-trial detention, the federal prosecutors service said.

"The detained suspects allegedly travelled to Somalia between 2012 and 2013 to join the al-Shebab there. They allegedly received weapons training in a camp of the group and then joined them in armed combat," prosecutors said in a statement.

The suspects were identified only as Steven N., 26, Abdullah W., 28, and Abdulsalam W., 23, in line with German practice of protecting the privacy of criminal defendants.