BEIRUT – Syria's military will "crush" armed rebels, President Bashar Assad's defense minister warned Saturday, as the regime shelled rebel positions in two cities and near the Lebanese border in a widening offensive.

Neighboring Turkey, meanwhile, set new rules of engagement after three shells from Syria hit Turkish territory Saturday. Turkey retaliated with artillery, as it has for the past four days, and Turkish Foreign Minister Ahmet Davutoglu said this would now be the standard response.

Davutoglu insisted that "we haven't taken a step toward war," but Turkey's threat to fire back for each errant Syrian shell was bound to keep border tensions high. Turkey is one of Assad's harshest critics and a key supporter of Syria's opposition.