Five NATO service members killed Wednesday when a roadside bomb exploded in eastern Afghanistan.

Five NATO service members killed Wednesday when a roadside bomb exploded in eastern Afghanistan.

A NATO statement did not identify the nationality of those killed but in Warsaw, Polish TVN24 — citing unnamed officials — said all five soldiers were Poles. If confirmed, it would be the highest one-time loss of Polish lives in Afghanistan.

Mohamad Ali Ahmadi, deputy governor of Ghazni province, said that Polish soldiers were attending a meeting Wednesday morning in Rawza district, located along the Ghazni-Kabul highway. One of their vehicles was hit by a roadside bomb, he said.

So far this year, 532 NATO service members have been killed in Afghanistan.

Meanwhile, an Afghan military spokesman said Wednesday the country's armed forces now number 180,000 troops, a significant step toward having enough troops to replace departing coalition forces.

Defense Ministry spokesman Mohammad Zahir Azimi said the troop numbers increased by more than 40,000 in 2011.

He said this brings the military closer to achieving the goal to have 195,000 Afghan troops in the field by next October.

Coalition forces, which started their drawdown this year, are counting on the Afghan army and police to take responsibility for security in the entire country by the end of 2014.