In its annual human rights report, the British Foreign Office added Syria to its "major countries of concern" list as part of the report and said it was "deeply concerned" by Syria's support for Hezbollah.
It noted Hezbollah fired nearly 4,000 rockets into Israeli territory, adding: "These indiscriminate rocket attacks killed approximately 40 Israeli civilians and injured up to 2,000 more."
However, the report's section on Israel and the occupied territories made no reference to Israel's military actions against the Shia militia.
Tony Blair, the UK prime minister, angered many during the 34-day war in July and August by refusing to call for an early halt to the fighting.
The conflict devastated much of Lebanon's infrastructure and killed 1,200 people there, mostly civilians, as well as 157 Israelis, mainly soldiers.
"If they had time to include Hezbollah and the 40 victims of Hezbollah rockets ... they had time to do something on what the Israelis did in Lebanon, especially given the disproportionate number of casualties," said Tom Porteous, London director of New York based Human Rights Watch.
"This report makes no specific mention of Israel's illegal targeting of Lebanese infrastructure"
Tim Hancock, Amnesty International UK's campaign director
Amnesty International also said it was concerned that several issues had fallen through the gaps.
"It is absolutely right that the government strongly criticise Hezbollah's rocket attacks, but deeply worrying that this report makes no specific mention of Israel's illegal targeting of Lebanese infrastructure...," said Tim Hancock, Amnesty International UK's campaign director.
Margaret Beckett, the UK foreign secretary, said the publication date of the report had prevented the subject from being covered in more detail.
"I would anticipate that would be more fully dealt with perhaps in next year's report since the timing of ... when this was produced was a little bit tight," she said.
However, Porteous said the numbers cited in the report which relate to Hezbollah's actions suggested it had gone to press around the middle of the war, which meant it was "inexcusable" that it was not balanced with Israeli comment.
"If they don't cover the human rights dimensions of such a huge story that the Middle East is looking at still with a great deal of anger... it is going to undermine their effort for hearts and minds in the war on terror," he said.