Bulgaria, which also suffered heavy losses and great material damage during Nicephorus' campaign, also had to reorganize its army and resources and was not able to advance until the next year. The Bulgarian attacks were concentrated mainly in Thrace, but also along the valley of the Strymōn (Struma) River. Many towns were seized and their population was sent far to the north to “Bulgaria across the Danube”. The attack created such panic among the Byzantine population that several towns were emptied even without being attacked by the Bulgarians. The attempts of Michael I to resist were fruitless – he organized an army but soon after he set off from Constantinople he had to go back due to a conspiracy.