ADDIS ABABA, Feb. 16 (Xinhua) -- Ethiopia's northern Amhara regional state has dropped charges against 224 people, state-affiliated media Radio Fana said on Friday.

Bisrat Abera, a senior official at Amhara regional state justice bureau, said the 224 were originally accused of participating in terrorism, vandalism and riots.

Many among Ethnic Amharas, who make up about 28 percent of Ethiopia's population, accuse the central government in Addis Ababa of economic and political marginalization.

Parts of Amhara regional state, along with parts of Oromia and Southern regional states, experienced deadly anti-government protests in 2016 that left hundreds dead and thousands others imprisoned.

The 2016 unrest was dubbed by analysts as the gravest challenge to the ruling coalition, Ethiopian People's Revolutionary Democratic Front, in 25 years.

It led to an imposition of martial law in October 2016, which was lifted in August 2017.

However, martial law was re-imposed on Friday after the reappearance in recent months of sporadic protests and strikes, especially in Amhara and Oromia regional states.

The persistence of deadly protests has renewed fears over Ethiopia's stability.