Ethiopian authorities have arrested more than 40 opposition party members and rounded up hundreds of students after riots this week that killed 41 people.
Police opened fire on rioters on Wednesday after student protests degenerated into the worst violence in the capital Addis Ababa since the overthrow of the Marxist regime in 1991.
Ethiopian Democratic Party (EDP) president Mr Admasu Gebyheu said he did not know why scores of members of his party had been arrested. But political analysts said EDP members were suspected of involvement in inciting the violence.
Ethiopia's government has repeatedly warned opposition parties not to exploit the violence that followed protests by students demanding political rights and an end to police brutality.
Media reports said hundreds of Addis Ababa University students had been driven 20 miles from the city to the Ethiopian Police College at Sendafa on Wednesday night.
Police entered St Mary's Church where students had sought refuge from the violence and forced them into military trucks, according to witnesses quoted in the Daily Monitornewspaper.
Authorities closed Addis Ababa university after Wednesday's clashes.
Police stormed the campus last week after student protests beating and injuring around 50 people.