A coffin of a French soldier killed in Afghanistan is carried during a funeral ceremony at Les Invalides in Paris on Thursday. (Michel Euler/Associated Press)

France held a commemoration ceremony on Thursday to honour 10 French soldiers killed in a gun battle with insurgents earlier this week in eastern Afghanistan, as questions are being raised over the official account of how the soldiers died.

French President Nicolas Sarkozy joined dignitaries and the soldiers' families inside Paris's Invalides palace, where France's war dead are honoured, as lines of uniformed men and women filled the boulevard outside the iconic building.

Under the great dome of the Napoleonic institution rested 10 identical coffins bearing the bodies of the soldiers, whose deaths mark the largest single loss of life for any of the international forces engaged in combat in Afghanistan in more than three years.

The solemn ceremony is an effort to soothe not just grieving families, but appease an increasingly wary nation at war, the CBC's David Common reported.

A majority of the French are opposed to the mission in Afghanistan, and the opposition Socialists are demanding a parliamentary committee meet to examine this week's battle.

Air support, Afghan army fired on French positions: survivors

The president's office said about 100 insurgents ambushed the group of French paratroopers on Monday during a joint reconnaissance mission with the Afghan National Army. Media reports said the battle, which continued into Tuesday, was in an area about 55 kilometres east of the capital, Kabul.

Though it was initially reported that nine of the 10 soldiers were killed in the battle's opening minutes, French media reports quoted surviving soldiers as saying many of the deaths only happened after several hours of fighting as ammunition for some of their weapons ran out.

Reports also emerged Thursday of Afghan officials claiming that four of the French soldiers were captured and then executed by the Taliban, the CBC's Common said.

Survivors were quoted as saying NATO air support arrived late and then bombarded French positions, while Afghan soldiers called in as backup reportedly also fired on the French.