LONDON, April 1 (Xinhuanet) -- A ninth man has been arrested in southeastern England on Thursday as British police were continuing their counter-terrorist operation.

    According to the Scotland Yard, the 27-year-old man was arrested in Crawley, West Sussex on Thursday afternoon. He was thefourth to be arrested in the town.

    The suspect, arrested "on suspicion of being concerned in the commission, preparation or instigation of acts of terrorism," was taken to a London police station to be interviewed by Anti-Terrorist Branch detectives, the police said.

    The arrest came after British detectives have been given three more days by the courts to question eight other suspects held overalleged bomb plot.

    The eight men, believed to be British citizens of Pakistani descent, were arrested on Tuesday in an anti-terror swoop in and around London.

    More than 700 police officers participated in the raids reportedly to be the biggest since the Sept. 11 attacks on the United States in 2001.

    Police also seized half a ton of ammonium nitrate fertilizer, often used as prime bomb-making material, when they were searching24 premises across southeastern England on Tuesday.

    Police believed the suspects, some of whom were arrested near Heathrow and Gatwick airports, could have been planning a truck orcar bomb aimed at civilians.

    British security sources said those arrested were "not thought to be al Qaida" or to have connections with foreign groups. But inquiries into their backgrounds continued as police began quizzing them. Enditem