Five Polish soldiers were killed Wednesday in a roadside bombing in Afghanistan.

It was the single deadliest day for Polish troops since their 2002 deployment to the country following the U.S.-led invasion of Afghanistan the year before.

The total number of Polish troops to die in Afghanistan now stands at 36.

Poland is one of the largest contributors to the NATO security force contingent with at least 2,500 troops in Afghanistan.

All NATO combat troops are scheduled to withdraw by the end of 2014.