Spain's Interior Ministry's statement on Wednesday said the man arrested in Britain was a 44-year-old Salafist Imam who led the group and was sought by several countries. 

He was detained in the city of Birmingham at Spain's request.

The statement said investigations began in 2015 when police detected videos promoted by the imam that documented the recruitment, indoctrination and sending of a young Muslim resident in Spain to Syria.

The ministry said the cell worked to recruit new members and actively promoted IS armed activities.

The four arrests in Spain occurred on the Mediterranean island of Mallorca, where the cell was allegedly based.