GAZIANTEP, Turkey — Syria pulled both Turkey and Israel closer to military entanglements in its civil war Monday, bombing a rebel-held Syrian village a few yards from the Turkish border in a deadly aerial assault and provoking Israeli tank commanders in the disputed Golan Heights into blasting mobile Syrian artillery units across their own armistice line.

The escalations that threatened once again to draw in two of Syria’s most powerful neighbors came hours after the fractious Syrian opposition announced a broad new unity pact that elicited praise from the big foreign powers backing their effort to topple President Bashar Assad.