Ethiopia has deployed soldiers against an armed faction of a recently-legalised opposition group that is robbing banks and attacking residents in the country's remote west, the government said on Wednesday.The violence in Oromia, Ethiopia's largest region, comes after separate ethnic clashes in the east temporarily shut the country's main fuel supply route, causing severe petrol shortages in the capital this week.The unrest across Africa's second most-populous country is the latest challenge faced by Prime Minister Abiy Ahmed, who has won Ethiopians over with dramatic reforms since taking office last year, even as ethnic violence surged.Those changes included welcoming home banned groups like the Oromo Liberation Front (OLF), which returned to Ethiopia after signing a peace deal last August.But last month, the group accused the government of breaching the agreement, and on Wednesday, a spokeswoman for Abiy said the military had been sent to Oromia's Kellem Wollega zone to stop a faction responsible for rapes, looting banks and blocking roads.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook. "Government has been patient for a very long time, trying to facilitate the different ideas," Billene Seyoum told journalists. "Those skirmishes are as a result of not heeding the call for peace."Authorities have detained 835 armed OLF members involved in the unrest, state-affiliated Fana Broadcasting Corporate reported.Meanwhile, a separate outbreak of ethnic conflict between the Afar and Somali peoples of eastern Ethiopia led to the closure of the trade route to Djibouti, whose Red Sea ports import most of Ethiopia's petroleum products.Such ethnic clashes have become increasingly common since Abiy's inauguration last April, and 1.4 million Ethiopians fled their homes last year, one of the world's highest numbers. The road closures caused blocks-long fuel queues to appear in the capital and largest city Addis Ababa, but Billene said representatives of the two ethnicities had reached an agreement."The road has been opened as well," she said.