Afghan defense officials on Wednesday announced at least 5 NATO troops were injured after an individual in Afghan national army uniform opened fire on coalition forces.

The officials further added the incident took place in Maidan Wardak province of Afghanistan.

Deputy Afghan defense ministry spokesman Dawlat Waziri said the incident took place late Tuesday evening inside a military base in Syedabad district in this province.

Mr. Waziri further added the assailant individual managed to flee the area and investigations have been launched in this regard.

This comes as Three British soldiers were killed on Sunday by an Afghan policeman in southern Afghanistan’s Helmand district.

That attack brought the total number of so called “Green-on-Blue” killings involving Afghan security officials attacking NATO allies to 26 in 18 incidents so far this year. That compares with 11 fatal attacks and 20 deaths the previous year. In 2007 and 2008 there were a combined total of four attacks and four deaths.