Spanish police arrested four people linked to a sophisticated social media campaign that recruited women to join terrorist groups such as Islamic state (Isis) on Tuesday, Spain’s interior ministery said.

The pre-dawn raids targeted two people in the northern African enclave of Melilla as well as two others in the provinces of Barcelona and Girona.

Authorities said that the two in Melilla, who managed several internet platforms that spread propaganda for terrorist groups such as Isis, “were dedicated to the recruitment of women, who after a process of indoctrination, would end up integrated into the terrorist group”.

Spanish civil guards in Melilla lead a detained man suspected of using social media to recruit people for violent groups such as Islamic state. Photograph: Reuters

The arrests in Spain come as authorities in Britain and Turkey scramble to locate three London schoolgirls feared to have travelled to Syria to join Isis militants after becoming radicalised online.

On Tuesday, Spain’s interior ministry said that one of the arrested in Melilla was the administrator of an online community that distributed propaganda material for Isis, which had more than 1,000 followers. A Facebook page linked to the arrested showed “a multitude of supporters” from across Europe, as well as Latin America and the Middle East.

The two arrested in Melilla also organised meetings at homes, showing potential recruits videos and materials from Isis in an effort to persuade them to travel to Iraq and Syria to join the conflict. They were successful in convincing a number of young people, said the ministry, who had begun making travel preparations.

In Catalonia, those arrested included a man who had edited and distributed videos to recruit potential jihadis, as well as a man who had identified himself in a CNN report as a supporter of Isis living in a western society.

Police arrest an alleged jihadi during the anti-terror operation in Barcelona. Photograph: Alberto Estevez/EPA

Authorities are now investigating links between those arrested in Melilla and Catalonia. They have refused to rule out the possibility of further arrests.

Spanish officials say some 80 nationals have travelled to Iraq and Syria to join Isis and other radical groups, a number far lower than those recruited from Britain, France and Germany. About a dozen are estimated to have returned to Spain.