Israel deliberately targeted civilian infrastructure and committed war crimes during the month-long conflict in Lebanon, according to an Amnesty International report.

The report said strikes on civilian buildings and structures went beyond "collateral damage" and amounted to indiscriminate and disproportionate attacks under the Geneva conventions on the laws of war.

Kate Gilmore, the Amnesty executive deputy secretary general, said the bombardment of power and water plants and transport links was "deliberate and an integral part of a military strategy".

"Israel's assertion that the attacks on the infrastructure were lawful is manifestly wrong," she said.

"Many of the violations identified in our report are war crimes. The pattern, scope and scale of the attacks makes Israel's claim that this was collateral damage simply not credible."

Amnesty called for an official UN inquiry into human rights violations on both sides of the conflict.

The report's authors described the destruction of up to 90% of some towns and villages in southern Lebanon, releasing aerial photographs that showed Beirut's southern Dahiya district had been transformed from a bustling suburb into a grey wasteland.

"In village after village the pattern was similar - the streets, especially main streets, were scarred with artillery craters along their length," the report said.

"In some cases, cluster bomb impacts were identified. Houses were singled out for precision-guided missile attack and were destroyed, totally or partially, as a result.

"Business premises such as supermarkets or food stores and auto service stations and petrol stations were targeted, often with precision-guided munitions and artillery that started fires and destroyed their contents."

Israel launched more than 7,000 air strikes against Lebanon during the 34-day war, and naval vessels launched 2,500 shells, the report said.

Around one third of the 1,183 people killed in Lebanon were children, while 4,054 people were injured and 970,000 displaced.

Lebanese estimates suggest that 30,000 houses, along with up to 120 bridges, 94 roads, 25 fuel stations and 900 businesses, were destroyed.

Two hospitals were destroyed and three others severely damaged, while 31 "vital points" - such as airports, ports, water and sewage treatment plants, and electrical facilities - were also completely or partially destroyed.

The overall cost of the damage amounted to $3.5bn (£1.8bn), the report said.

Around 4,000 Hizbullah rockets were fired at northern Israel during the conflict, killing around 40 civilians. Up to 300,000 people in northern Israel were driven into bomb shelters by the fighting, and 117 soldiers died.

The Amnesty report said Israeli military policy seemed directed at destroying Lebanese popular support for Hizbullah, a tactic prohibited by the Geneva conventions.

"The widespread destruction ... in addition to several statements by Israeli officials, suggests a policy of punishing both the Lebanese government and the civilian population in an effort to get them to turn against Hizbullah," it said.

Red Cross officials were quoted as saying that people left behind in inaccessible villages in southern Lebanon had been unable to get hold of fresh water.

Refugees from the border village of Rmeish had told Red Cross delegates that locals had had to drinking foul water from an irrigation ditch.

The report's allegation of disproportionate action echoes comments made during the conflict by international observers including French, Russian and EU officials and the UN humanitarian chief, Jan Egeland.

However, the British government has avoided the term, which could be considered an accusation of war crimes, although former the foreign secretary Jack Straw and the Conservative foreign affairs spokesman William Hague both used it.