The security police said the arrest in the Stockholm suburb of Rinkeby is linked to an investigation in southwest Sweden where another man was detained on similar charges in May.

Police had issued an arrest warrant and said several other people also will be questioned.

Prosecutor Agnetha Hilding Qvarnstrom said the suspect is a Swedish citizen but declined to give more details.

It wasn't immediately clear how the suspect responded to the allegations.

Since the 1990s, more than 50,000 Somalis have fled to Sweden, Denmark and Norway from the war in their homeland.

Police have expressed concerns about the radicalization of young men in Somali immigrant communities and say about 20 people have left Sweden to join Islamists waging an insurgency against Somalia's government. So far, four people identified as Swedish citizens have been killed in the insurgency, the security police said Tuesday.

In December a Danish man of Somali descent killed 24 people in a suicide bombing in Mogadishu. A Somali man is also facing preliminary charges of terrorism and attempted murder in Denmark for a break-in at the home of a cartoonist who caricatured the Prophet Muhammad (pbuh).