"Evidence that Gaddafi's forces are now targeting cluster bombs on civilian neighbourhoods of Misrata is likely to fuel calls for accelerated action from NATO, whose military actions and international sanctions against the regime have succeeded in weakening Gaddafi but have failed so far to secure a decisive breakthrough in the conflict. Human Rights Watch released photographs and testimony from its arms expert which it said confirmed witness reports that the munitions, banned by more than 100 countries, were being fired on the city. Cluster bombs explode in midair, indiscriminately throwing out dozens of high-explosive bomblets which cause widespread damage and injuries over a large area. The sub-munitions often fail to explode on impact but detonate when stepped on or picked up... Rebel fighters in Misrata have called on NATO to step up its airstrikes on loyalist positions around the city to protect the civilian population and aid the resistance... The shift by the US, Britain and France towards regime change as a goal of the NATO operation is controversial among some countries that backed UN resolution 1973, which authorised military action to protect Libya's civilian population... NATO itself is in a quandary about how to break the military deadlock in Libya. UN resolution 1973 specifically rules out a "foreign occupation force". Amid mounting calls for a NATO ground presence in Libya, politicians, lawyers and military chiefs are poring over the resolution's semantics to establish whether such a step – with its enormous political and military risks and implications – could be taken... Mohamed (a rebel spokesman) said the rebel opposition in Misrata had appealed to NATO to send ground troops to relieve the city. They were, he said, grateful for the international coalition's military intervention. "But we're surprised. And we're angry. We are angered by the lack of hits on Gaddafi's troops by NATO forces..."