Around 20 people demonstrating against one of the world's largest commercial arms bazaars were arrested yesterday on the first day of the Defence Systems and Equipment International Exhibition at London's Docklands.

The four-day event features everything from tanks and warships to logistics software and vehicles for internal security duties.

Among the nations invited to attend are Libya, China, Saudi Arabia and Indonesia, all of which have questionable human rights records.

Up to 20 protesters were arrested on suspicion of breach of the peace after staging a sit-down outside the Excel Centre, the headquarters for the global weapons market. Two others were charged with criminal damage after throwing paint at the entrance to the nearest underground station to the event.

Organisers Reed Elsevier, who also publish the Lancet medical journal, have bowed to pressure and said they will no longer host the exhibition after this year.

Dr Bill Wilson, SNP West of Scotland MSP and a long-term campaigner against weapons sales, welcomed the news that no new sponsor had so far come forward to stage future exhibitions. He said: "The argument that the arms trade is important for UK jobs and the economy is akin to that used in the past to justify the slave trade. I hope we are now seeing a new dawn."

The Campaign Against the Arms Trade said it expected Reed Elsevier to struggle to find a buyer for the exhibition.

Britain earns more than £1.4bn a year in overseas arms sales and more than 300,000 UK jobs are directly or indirectly dependent on defence contracts at home and abroad.