'fierce violence' is correct and can be used in written English.
You can use it to describe a violent event, especially one characterized by extreme force. For example, "The protestors were met with fierce violence from the police."
Fierce violence erupted around the elections, resulting in the deaths of scores of people.
BEIRUT, Lebanon — A team of observers from the Arab League traveled to the embattled Syrian city of Homs on Tuesday in a visit that quieted days of fierce violence but also provided hints of the potential challenges of a group trying to monitor a withdrawal of the government's security forces in towns across the country.
The killings at the school in Beit Hanoun, where hundreds had taken refuge from the fierce violence in the area, have led to deep international concern with the UN Secretary General, Ban Ki-moon and Valerie Amos, the organisation's humanitarian chief, among those who strongly condemned the attack.
Raqqa has seen fierce violence between ISIS and rival groups fighting the forces of President Bashar al-Assad.
The city has also seen fierce violence between Isis and rival groups fighting the forces of Syrian President Bashar al-Assad.
But however sophisticated the campaign is, when the hatred is so fierce, violence is inevitable.
And in Diyala, Shiites dominate the government even though Sunnis account for a majority in the region, a situation that has exacerbated the fierce sectarian violence there.
Despite its fierce campaign of violence, the group has an undefined structure and no clear chain of command.
The P.C.C. stunned São Paulo in 2006 when it coordinated its fierce outbreak of violence, in which police officers were also targeted for execution.
Though there were fierce struggles, the violence was isolated and the Ukrainian government said its main goal was to remove roadblocks rather than attack protesters.
The trial continues to excite significant interest in South Africa, where it has provoked a fierce debate about violence and domestic abuse, and internationally.
