Rights groups say 140 people killed in recent weeks as government moves forward with controversial development plans.
At least 10 people, including police officers and civilians, have been killed in northern Ethiopia after days of protests, according to local sources.
Demonstrations on Thursday and similar protests in recent days in the city of Gondar were against what protesters see as the erosion of their ethnic identity.
The government said five police officers and one civilian were killed, while activists in the city said at least 20 people had been killed, including security forces.
The anti-government protests started after security forces arrested members of the Welkait community. Members of the Amhara ethnic community also joined the protests.
Information Minster Getachew Reda said at a press conference on Friday morning that the government had received reports that six members of an “illegal committee” were involved in murder and kidnapping, and had a large cache of weapons.
The government said the men were being supported by the Eritrean government.
Al Jazeera could not independently verify the reports.
“The government is saying they were trying to arrest people linked to a terrorist organisation. We’ve spoken to some people who say tourists have been moved out of the city to safe areas. The city is under lockdown,” Al Jazeera’s Charles Stratford, reporting from the capital Addis Ababa, said.
Ethiopia has seen other protests this year in Gondar and elsewhere, Stratford said. Human rights organisations say that 300 people were killed during protests by the largest ethnic group, the Oromo.
Images posted online and said to be from Gondar showed burned-out vehicles and armed men firing guns in the air as hundreds of other people cheered them on.
The Welkait ethnic group live between the Amhara and Tigray regions. Many Welkait and Amhara opposition groups accuse the government of being dominated by Tigrayan politicians.
The Welkait accuse the government of forcing them to be part of Tigray and not recognising their ethnic group. Welkait opposition groups want to join the Amhara. The government has refused.
“They say that they are being ignored by the government – the government that they allege is dominated by other ethnic groups from the north,” Stratford said.
The violence prompted the US embassy in Ethiopia to issue a temporary advisory warning against travel to the city centre of Gondar and areas where “violent demonstrations” have been reported.
“The embassy recommends all US citizens travelling to or resident in the Gondar area evaluate their personal level of safety and to avoid demonstrations or large gatherings,” the advisory issued on Wednesday said.