The Ottoman troops seized the fortresses of Shumen , Madara , Venchan and Ovech .
The Ottomans reacted by sending a 30,000 - strong army , under the command of the grand vizier Ali Pasha , to the north of the Balkan Mountains .
The Ottomans troops seized the fortresses of Shumen , Madara , Venchan and Ovech .
The Ottomans reacted by sending a 30,000 - strong army , under the command of the grand vizier Ali Pasha , to the north of the Balkan Mountains .