Spanish police have arrested three suspected members of Al-Qaeda carrying explosives in the southern province of Cadiz, a court official told AFP Thursday.

The source could not provide further details but Spanish radio station Cadena Ser, citing police, said the suspects were two Chechens and a Turk, who were carrying explosives and poison when they were arrested.

The three men had received training at an Al-Qaeda camp in Pakistan, were experts at handling explosives and making poison, and were planning to carry out an attack in Spain, the radio station added.

One of the suspects was arrested at an apartment they were renting in the southern town of La Linea de Concepcion in Andalucia, the station said.

The interior ministry refused to confirm the report but announced that Interior Minister Jorge Fernandez Diaz would hold a press conference at 1:00 pm (1100 GMT).

Several Islamic extremists have been arrested in recent years in Spain, especially in Catalonia in the northeast.

According to Spanish media however, this is the first time extremists have been arrested in possession of explosives.

In March police arrested a suspected member of Al-Qaeda in the eastern city of Valencia on terrorism charges. They said he ran one of the world's most important jihadist forums dedicated to recruitment and indoctrination.

The man, who has Saudi citizenship, was known within the organisation as "Al-Qaeda's librarian", Diaz told reporters at the time.

On March 11, 2004, bombs exploded on packed commuter trains in Madrid, killing 191 people and wounding 1,841 others in a strike by a local cell of Islamic extremists carried out in the name of Al-Qaeda.

Twenty-one people, mostly Moroccans, were convicted of involvement in those attacks.