sentences:  It was the forces under Ter-Gukasov, numbering at around 13,000 soldiers, stationed near Yerevan, that commenced the first assault into Ottoman territory by capturing the town of Bayazid on 27 April 1877.Capitalizing on Ter-Gukasov's victory there, Russian forces advanced, taking the region of Ardahan on 17 May; Russian units also besieged the city of Kars in the final week of May, although Ottoman reinforcements lifted the siege and drove them back.Along the way to Erzurum, Ter-Gukasov managed to capture the villages of Karakilise, Diadin, and the Eleşkirt valley.