WASHINGTON, April 19 (Reuters) - Air strikes that killed around 40 people in a crowded vegetable market in rebel territory in Syria were likely carried out by Syrian government forces, U.S. State Department spokesman John Kirby said on Tuesday.

Despite the bombing of the market in Maarat al-Numan in Idlib province, which a monitoring group said it believed was the deadliest single attack since a partial ceasefire began on Feb. 27, Kirby said the United States believed the so-called cessation of hostilities was still largely holding but fragile. (Reporting by Arshad Mohammed and Lesley Wroughton, editing by G Crosse)

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