An Oslo court decided yesterday to extend by four weeks the solitary confinement of three men suspected of links to Al-Qaeda and planning an attack on Norway, the news agency NTB said.

The suspects have already spent four weeks in solitary in order to prevent them colluding over their testimonies.

Police told the court in a closed hearing that they had fresh evidence against the three, after which the court ordered the men held for another four weeks.

All three suspects were arrested on July 8 as part of a Norwegian Security Police investigation. Police say they have links to Al-Qaeda and were planning one or more attacks on Norwegian soil.

In isolated detention the men are only allowed contact with their lawyers, and have no access to any news or computers.

The explosives the suspects had prepared were reportedly rendered harmless by the Norwegian Security Police, who swapped the bomb-making chemicals they had ordered at pharmacies with a harmless ­liquid.