Police have arrested five people suspected of forming an Islamic State cell and promoting Islamist militancy in Spain, Belgium and Germany, the Spanish Interior Ministry said on Wednesday.

Three of them were detained in Spain - two of them in Barcelona and one in Spain's North African enclave of Melilla - one in Brussels and another in Wuppertal, Germany, it said.

The group used social media, specifically a Facebook page "Islam en Espanol" (Islam in Spanish), to glorify the Islamic State and spread the message of the militant group that operates out of Syria and Iraq, the ministry said.

They are accused of commissioning attacks, radicalization, promoting Islamist militancy and acting as go-betweens for Islamic State recruitment in Europe, the ministry said.

Spain has arrested 34 people with suspected connections to Islamist militancy this year.