The whistleblowing website WikiLeaks says it plans to release a secret military video of one of the deadliest US air strikes in Afghanistan in which scores of children are believed to have been killed. WikiLeaks announced the move in an email to supporters. It said it fears it is under attack after the US authorities said they were searching for the site’s founder, Julian Assange, following the arrest of a US soldier accused of leaking the Afghanistan video and another of a US attack in Baghdad in which civilians were killed. WikiLeaks released the Baghdad video in April, prompting considerable criticism of the US military. It says it is still working to prepare the film of the bombing of the Afghan village of Garani in May 2009. The Afghan government said about 140 civilians were killed in Garani, including 92 children. The US military initially said that up to 95 people died, of which about 65 were insurgents. However, American officials have since wavered on that claim and a subsequent investigation admitted mistakes were made during the attack. The video could prove to be extremely embarrassing to the US military and risks weakening Afghan support. Last week, it was revealed that US authorities are trying to make contact with Assange to press him not to publish information the Pentagon says could endanger national security. Assange cancelled an appearance in Las Vegas last Friday.