Michael Euler, Associated Press
Coffins of French soldiers who were killed in Afghanistan are carried during a funeral ceremony Thursday at Les Invalides in Paris. French officials faced increasing pressure Thursday to reconstruct and explain the ambush east of Kabul on Monday that killed 10 troops and injured 21 others. President Nicolas Sarkozy led the solemn funeral ceremony to honor the victims Thursday.

PARIS (AP) — A French patrol marches up a rocky and dusty Afghan mountain pass. Suddenly, Taliban insurgents open fire from front and back, setting off an hours-long gunfight — the deadliest for allied forces in Afghanistan in more than three years.

French officials faced increasing pressure Thursday to reconstruct and explain the well-planned and unusually bloody ambush east of Afghan capital Kabul days earlier that killed 10 French troops and injured 21 others.

President Nicolas Sarkozy led a solemn funeral ceremony to honor the victims at the Invalides complex in Paris, and vowed that France will not pull out of the U.S.-led fight against terrorism based in Afghanistan.

"We don't have the right to lose there," he said.

Also Thursday, the U.S.-led coalition said it had killed more than 30 insurgents in eastern Afghanistan — fighters an Afghan governor said were responsible for the Monday attack that killed the French troops.

The ambush and ensuing gunbattle, which French officials say also killed about 30 insurgents, opened a window into the swelling maelstrom of violence in Afghanistan and exposed how allies are under new strains from a resurgent Taliban. Two attacks Thursday killed six NATO soldiers, officials said.