Authorities in a Spanish enclave in North Africa have arrested a suspect in last year's Madrid train bombings (search), the seventh person detained this week, police said.

The March 11 train bombings, which killed 191 people and wounded more than 1,500, have been claimed in videos by militants saying they acted on behalf of Al Qaeda (search).

Rachid Mohamed Kaddur, a 35-year-old Spaniard, was arrested Thursday night in Melilla (search), one of two Spanish enclaves on the coast of Morocco, police said.

Kaddur and a man arrested Wednesday outside Madrid are suspected of having met with a key suspect in the bombings the day before the attack, police said.

The latter is Abdennabi Kounjaa, one of seven suspects who blew themselves up in an apartment in the Madrid district of Leganes on April 3 as police came to arrest them.

Also Friday, a family of four Moroccans arrested Tuesday in Madrid on suspicion of having links to the bombings were to go before the judge investigating Spain's worst terrorist attack.

Hours later Monday, another Moroccan, Youssef Belhadj, who authorities believe is an Al Qaeda figure mentioned in a video claiming responsibility for the bombings, was detained in Belgium on an international arrest warrant issued by Spain.