A coalition of countries including Britain on Friday defeated an attempt by the US, Russia, China and Israel to get an international agreement approving the continued use of cluster bombs. The weapons, which have been used in Iraq, Afghanistan and Lebanon scatter "bomblets" over a wide area, maiming and killing civilians, notably children, long after they have been dropped and are banned under a 2008 convention which was adopted by the UK and in more than 100 countries. The US, refused to sign and in negotiations in Geneva, over the past two weeks pressed for a protocol to be added to a UN convention to provide legal cover for the continuing use of cluster munitions. But smaller countries, supported by agencies including Amnesty and Oxfam, refused to give way.

Thomas Nash, director of Article 36, a group which coordinated opposition to cluster munitions, said: "The rejection of this attempt to set up a weaker standard on cluster bombs shows that states can act on the basis of humanitarian imperatives and can prevail in the face of cynical pressure from other states".

He added: "It shows that it is not only the US and other so called major powers that call the shots in international affairs, but that when small and medium sized countries work together with civil society and international organisations we can set the agenda and get results".

The US was supported in the Geneva talks by other cluster bomb manufacturers – including Russia, China, Israel, India and Pakistan.

They were backed by countries which had signed the 2008 convention, including France, Germany, Italy, Portugal and Australia, conference observers said.

The Foreign Office had said that the British government would not accept the proposed protocol unless it provided clear humanitarian benefits.

The US and its supporters argued that their proposal would allow the use of cluster bombs manufactured after 1980 and that these had a less than 1% failure rate. Opponents said that most bombs produced before 1980 are unusable and that modern cluster munitions have failure rates much higher than the manufacturers claim.

If the US bid had been approved, international legal cover would have been given to such weapons as the BLU-97 "combined effects" bomb which contains bomblets that, as they fall, fragment and can turn into an incendiary weapon.

The unexploded bomblets have the appearance of yellow drink containers and are attractive, often picked up by children who mistake them for toys. However, the consequences are lethal, often resulting in maiming or even fatalities.