The Wikileaks founder, Julian Assange, said today that the organisation is working through a "backlog" of further secret material and was expecting a "substantial increase in submissions" from whistleblowers after one of the biggest leaks in US military history.

Speaking in London after his website published more than 92,000 classified military logs relating to the war in Afghanistan, Assange said that he hoped for an "age of the whistleblower" in which more people would come forward with information they believed should be published.

Assange said that the site, which currently operates with a small dedicated team but has a network of about 800 volunteers, had a "backlog" of more material which only "just scratched the surface".

While he would not be drawn into commenting on the nature of the material, he said that the organisation held "several million files" that "concern every country in the world with a population over 1 million".

He said the site had undergone a "publishing haitus" since December during a period of re-engineering. Assange suggested a clear step-up of operations and said that there were difficulties in changing from a small to large organisation while ensuring it would still be able to work in a secure way.

"My greatest fear is that we will be too successful too fast and won't be able to do justice to the material," he said.

He said that from past experience the organisation was expecting more material to add to the backlog. He said that after the site leaked details of one incident that killed 51 people in Afghanistan, "we received substantial increase in submissions".

"Courage is contagious," he added. "Sources are encouraged by the opportunities they see in front of them."

He said that a further 15,000 potentially sensitive reports had been excluded from today's leak and were being were being reviewed further. He said some of this material would be released once it was deemed safe to do so. He added that the majority of this material was threat reports and that it included more than 50 embassy cables.

Assange's plans will cause concern in government agencies, which argue that the site's leaks are "irresponsible" and pose a threat to military operations in Afghanistan and elsewhere. But Assange and said that the site applied "harm minimisation" procedures before publishing material.

"We don't do things in an ad hoc way," he said. We've tried hard to make sure that it puts no innocents at harm. This material is over seven months old so it's of no operational significance, although it's significant for journalistic investigation."

Assange said that although the raw material was there, the real work would now begin to make sense of its scale. He said that a single report of an incident on 9 August 2006 – part of Operation Medusa – had a kill count of 181 but from reports of the official death count, the two figures didn't tally. "We add up all these deaths and we get around 80. The other 101 are unexplained."

He added that there was no single issue brought to light by the material. "There is no single damning, single person, single mass killing. That's not the real story. The real story is that it's war. It's the continuing small events, the continuing deaths of civilians, children and soldiers."

Assange said that although he did not believe that the material was a threat to the US military operation in Afghanistan it was clear that it "will shape a new understanding of the war" and made "less room to gloss over what has happened in the past".

He added that although seven months had passed since the last revealed file, he did not believe that changes in military strategy made by Barack Obama necessarily meant a change on the ground. Assange said that there was a problem with the way operations were reported from the ground.

"Military units when self-reporting speak in another language, redefining civil casualties as insurgent casualties ... When US military report on other US military they tend to be more frank. When they report on ally military units, for the example the UK or the Polish, they're even more likely to be frank. But when they report on the Taliban then all evil comes out. Internal reporting is not accurate. The cover-up starts at the ground. The whole task is to make the war more palatable."

He added: "What we see is the US army as a huge boat that's hard to turn around. It's hard to have a new policy and enact change. [Change] has to come from the bottom not the top."