In Libya, at least four civilians have been killed following heavy shelling by forces loyal to Libyan leader Moamer Gaddafi in the besieged third city of Misrata. The city is about 215 kilometres (130 miles) east of Tripoli and the rebels' last major bastion. Misrata has seen fighting for more than 40 days since the start of the uprising against Gaddafi on17th February. The clashes came as a debate raged over how well NATO air forces are enforcing a UN-mandated no-fly zone. NATO's role in the conflict came under renewed scrutiny and on the diplomatic front both the European Union and the African Union announced initiatives to help bring about a ceasefire. NATO was already facing criticism by the opposition after its warplanes hit rebel tanks on Thursday near Brega, killing four people, wounding 14 and leaving six others missing.