Security staff stand guard following a terrorist attack in central Barcelona, Spain. Picture: Xinhua/Han Chong

Madrid - An alleged member of an Islamist group that carried out the Barcelona van attack told a Spanish court on Tuesday that the group had been planning a much bigger attack using explosives, a judicial source said.

The testimony to Spain's High Court came from Mohamed Houli Chemlal, who was arrested after being hurt in a blast at a house in Alcanar, southwest of Barcelona, a day before Thursday's van attack on the crowded Las Ramblas boulevard in Barcelona which killed 13 people.