April 4 (Bloomberg) -- Serhane Ben Abdelmajid, identified by Spain as the leader of the March 11 terrorist attacks that killed 191 people in Madrid, was among those who died yesterday in a police raid, Spanish Interior Minister Angel Acebes said.

Ben Abdelmajid, known as ``the Tunisian,'' was among four terrorists who killed themselves by detonating explosives as police tried to enter their apartment in the Madrid suburb of Leganes, Acebes said. The blast also killed a police officer.

The raid was part of the investigation following Spain's worst terrorist attack, which injured more than 1,500 people. Arrest warrants were issued for six suspects in connection with the March bombings. Since the attack, 24 people have been arrested, including two Syrians, two Indians, two Spaniards and 15 Moroccans. Some have been released.

``After the arrests made and the suicide of the terrorists yesterday, the main terrorists behind March 11 are detained or dead,'' Acebes said at a press conference in Madrid.

The March 11 explosions were Europe's most deadly terrorist attack since the 1988 bombing of Pan Am Flight 103 over Lockerbie, Scotland, which killed 270 people.

The Moroccan Islamic Combatant Group is the main suspect in the March 11 attacks, Acebes said earlier this week. Police found a videotape two days after the March 11 bombings claiming the attacks in the name of al-Qaeda.

Dynamite, Detonators

The explosives and detonators found in the flat in Leganes are the same type as those used in the March 11 attacks and found Friday on rail tracks linking Madrid and Seville, Acebes said. Police found in the flat 10 kilograms of dynamite, 200 detonators, and a belt loaded with 2 kilograms of explosives.

``They were ready to commit new attacks,'' Acebes said. ``The police yesterday saved a lot of lives.''

The investigation is still under way and police are trying to find two or three more suspects, collaborators and links with other terrorist groups, Acebes said.