Afghanistan's interior ministry said on Thursday it would dissolve a security company whose employees were detained in Kabul with 30 unregistered AK-47 assault rifles.

The detained suspects, two Britons and two Afghans, were unable to provide documentation for the ammunition and weapons, and most of the guns had their serial numbers removed, ministry spokesman Sediq Sediqqi told a news conference.

Kabul police will be calling on the head of this company very soon and they have to pay all the dues they owe to the Afghan government and they cannot operate after that, he said.

The men's employer, security firm Garda World, said it only had the 30 rifles on a temporary loan to test them, because they were looking to purchase new guns for Afghan employees.

We are not the owners of the guns and we firmly believe we will be exonerated, an official from the firm who asked not to be identified told Reuters. We have always cooperated with the Afghan authorities and will continue to do so.

Police made the arrests in the eastern part of the capital, where there are several foreign military bases.

Dozens of private security firms were set up in the years after the Taliban government was toppled, providing security for businesses, embassies, aid projects and government offices.

In August 2010, Afghan President Hamid Karzai said he wanted private security firms - with the exception of firms working inside compounds used by embassies - to close by the end of that year. The deadline was later pushed back to March 2012.

Karzai has said the security firms are the biggest barrier to the development of local police forces. They are accused of using heavy-handed tactics, putting ordinary Afghans at risk.

A branch of the police, the Afghan Public Protection Force (APPF), is scheduled to take over the work done by private security firms, but some in the industry do not believe the APPF will be ready in time.

(Editing by Ron Popeski)