Classified UK Ministry of Defense documents containing details about HMS Defender and the British military in Afghanistan have been found at a bus stop in Kent in the United Kingdom, the BBC reported.

According to the report, one set of documents discusses the likely Russian reaction to the ship’s passage through Ukrainian waters off the Crimea coast on Wednesday while another details plans for a possible UK military presence in Afghanistan after the US-led NATO operation ends.

The government said an investigation had been launched.

A Ministry of Defence spokesperson said an employee had reported the loss of sensitive defence papers, adding: “It would be inappropriate to comment further.”

BBC reported that the documents, almost 50 pages in all, were found in a rain-soaked heap behind a bus stop in Kent early on Tuesday morning.

A member of the public, who wishes to remain anonymous, contacted the BBC when he realised the sensitive nature of the contents.

The BBC believes the documents, which include emails and PowerPoint presentations, originated in the office of a senior official at the Ministry of Defence (MoD).

According to the BBC, most of the papers are marked “official sensitive”, a relatively low level of classification used, according to the government, “where there is a clear and justifiable requirement to reinforce the ‘need to know'”.

But one document, addressed to Ben Wallace’s private secretary, and marked “Secret UK Eyes Only”, outlines highly sensitive recommendations for the UK’s military footprint in Afghanistan, following the withdrawal of all foreign troops by September 11.

BBC reported the document discusses an American request for British assistance in several specific areas, and addresses the question of whether any British special forces will remain in Afghanistan once the withdrawal is complete.

Media reports have already suggested Britain is considering leaving some forces behind.

Due to the sensitivity of the document, the BBC has decided not to report details which could endanger the security of British and other personnel in Afghanistan.

“Any UK footprint in Afghanistan that persists… is assessed to be vulnerable to targeting by a complex network of actors,” it says, noting that “the option to withdraw completely remains.”

Afghanistan, it says, is already becoming more dangerous.

According to BBC, the documents stated the reduced presence of NATO forces “is already impairing the situational awareness that we (and the US) used to enjoy across the country”.