ADDIS ABABA (Reuters) - Ethiopia said its troops were marching on the capital of the Tigray region on Tuesday after a deadline for rebel forces to surrender passed in a two-week conflict shaking the Horn of Africa and alarming the world.“The final critical act of law enforcement will be done in the coming days,” Prime Minister Abiy Ahmed said. Later on Tuesday, Abiy’s special task force on the Tigray conflict accused rebel forces of destroying bridges connecting the regional capital Mekelle with the rest of the country in attempts to hold back federal government forces. “Anxious about (our) advance, the junta has destroyed four bridges that lead to Mekelle,” it said, adding that the TPLF had also destroyed the section of a main road eastwards to Mekelle between the towns of Shire and Axum. Shire was under federal control, the task force reported earlier in the day. “The TPLF junta will soon be held accountable for destroying this infrastructure and for crimes it has committed so far.”