The 391,832 reports, titled "The Iraq War Logs", document the war and occupation in Iraq from 1 January 2004 to 31 December 2009. They are "the largest classified military leak in history," said Wikileaks.
Speaking to the BBC's The Andrew Marr Show, deputy prime minister, Nick Clegg, said the logs need to be looked at.
"We can bemoan how these leaks occurred, but I think the nature of the allegations made are extraordinarily serious. They are distressing to read about and they are very serious," said Clegg, according to The Guardian.
In a statement, the Ministry of Defence (MoD) warned the releases "put the lives of UK service personnel and those of our allies at risk and make the job of armed forces in all theatres of operation more difficult and more dangerous," reported the BBC.
Run from Sweden, Wikileaks previously published 77,000 US military documents on the war in Afghanistan.