The Lebanese government and Hezbollah have condemned a watchdog report which criticises Hezbollah's conduct in the conflict against Israel last year.
A woman walks through the rubble in Beirut, summer 2006
The report by Human Rights Watch accuses Hezbollah of "indiscriminately and at times deliberately" targeting Israeli civilians.
The group called off the report's launch in Beirut on Thursday on hearing that Hezbollah planned to disrupt it.
Human Rights Watch accused Hezbollah of trying to silence criticism.
The report says Hezbollah forces fired long-range rockets that "were highly inaccurate and could not distinguish between civilians and military objectives", resulting in at least 39 Israeli civilian deaths.
The New York-based group says Hezbollah's justifications for attacking Israeli towns - as a response to what Human Rights Watch has characterised as indiscriminate Israeli fire into southern Lebanon - have no legal basis under the laws of war.
A spokesman for Hezbollah, Hussein Rahal, said Human Rights Watch should start by criticising Israel.
"We were the victims during this war and people have a right to defend themselves," he told AFP.
"We did not target civilians but Israel on the other hand did target the civilian population in Lebanon."
Criticism also came from the Lebanese prime minister's office.
"Israel during the attacks of July 2006 violated all international conventions," it said in a statement.
Human Rights Watch is due to release a big report, into civilian deaths in Lebanon during the conflict, in September.
The group said it cancelled its Beirut news conference on Thursday when it heard that Hezbollah was planning to disrupt it, and the hotel therefore refused to host the event.
In a statement, HRW said its focus was on protecting civilians, not on taking sides in a conflict.
"Hezbollah is trying to silence criticism of its conduct during the 2006 war," said Sarah Leah Whitson, director of the group's Middle East division.
"The fairness and accuracy of our reporting will speak for themselves, whether we hold a press conference or not."