Without ruling out the participation of other terror groups, Spanish Interior Minister Angel Acebes said the attacks that hit Madrid on March 11 might be blamed on the Moroccan Islamic Combatant Group, the forerunner of which was also blamed for last year's suicide bombings in Casablanca.

    He said the group is now the "priority" of the investigation. "Other options are not being ruled out, but primarily the investigation is going to go in this direction," Acebes told reporters.

    The Moroccan Islamic Combatant Group is considered the first radical jihad movement in Morocco. The name of the group had surfaced in Spanish news reports, but this was the first time a Spanish government official publicly identified it as the focus of investigation into the train bombings, which killed 191 people andwounded more than 1,400.

    Acebes said witness testimony and the discovery of a rural house where the attackers were believed to have assembled the backpack bombs used in the attacks have led investigators closer to unraveling the plot behind the bombings.

    "The investigation is advancing. In 18 days we have arrested 23 people including some of the chief perpetrators of the attacks," Acebes said.

    Moroccan, British and German authorities were involved in the investigation, he added.

    The interior minister also noted that so far they had arrested two Spaniards, two Indians, two Syrians and 15 Moroccans in connection with the train bombings.

    Meanwhile, official sources said that an Arab and a Spaniard were arrested Tuesday by the Spanish police as suspects in connection with the Madrid bombings.

    Preliminary inquiries revealed that one of the detainees is the brother-in-law of Jose Emilio Suarez, who had been accused of providing explosive material for the blasts.

    Court officials said Judge Juan del Olmo would issue an international arrest warrant Tuesday for five other suspects.

    The Spanish news agency Efe said Abdelkrim Mejjati, a 36-year-old Moroccan believed to have masterminded the attack, was among the five being sought.

    Moroccan authorities have said Mejjati was linked to the suicide bombings in Casablanca, which killed 45 people, including 12 suicide bombers. But they said his role in the Madrid attacks was unclear. Enditem