Madrid, March 18 (Reuters): Spanish police arrested two Moroccans and two others today as they investigated last week’s suspected al Qaida-linked Madrid train bombings that killed 201 people, judicial sources said.

State radio said one of those arrested was suspected of playing a direct role in the Madrid bombings and was also wanted over last May’s Casablanca bombings — the latest indication investigators believe the two attacks are linked. Three of the four were detained near Alcala de Henares, a commuter town near Madrid where the trains bombed a week ago picked up passengers.

The fourth unidentified man — detained in the northern city of Gijon — was the one state radio said was linked to both the Madrid and Casablanca attacks. They are the first arrests in the case since Saturday’s detention of three Moroccans and two Indians, who were facing a closed-door preliminary hearing at which a judge will decide whether to release them or keep them in custody. More than 1,750 people were also injured in the Madrid attacks, western Europe’s bloodiest guerrilla attack since the 1988 Lockerbie plane bomb

Interior minister Angel Acebes said the investigation was making progress and at an important stage, but gave few details. “There are results... Some of those arrested have been handed over to the courts and other arrests are happening,” he told a news conference after the weekly cabinet meeting. Court sources said Spanish High Court judge Baltasar Garzon opened a secret investigation into the Casablanca bombings the day after they occurred in May last year. The Casablanca blasts killed 45 people, including 12 suicide bombers. Four Spaniards were among the dead.