A roadside bomb killed five Polish soldiers in eastern Afghanistan today. All five were members of the Nato-led International Security Assistance Force (ISAF).
It is Poland's largest loss of life in a single incident since it joined the ISAF almost a decade ago.
"This is very sad information for the Polish soldiers, for the whole of Poland, and especially for the families who are being informed of the fact right now," Prime Minister Donald Tusk told a news conference in Katowice, southern Poland.
"The bomb had to be of a very significant power as the vehicles the Polish soldiers use are generally well-protected against this type of attack," he said.
Poland has about 2,475 troops in Afghanistan, most of them stationed in Ghazni province, southwest of the capital, Kabul. A total of 36 Polish soldiers have now been killed in Afghanistan, according to Poland's defence ministry.
Reuters