BELFAST — Police in Northern Ireland deployed water cannons for the first time in six years Thursday as they tried to disperse protesters who hurled stones, fireworks and gasoline-filled bottles at officers during another night of violence in Belfast.

The violence erupted last week as anger over COVID-19 restrictions and post-Brexit trade rules fueled tensions between the Protestant and Catholic communities in Northern Ireland.

While the crowds appeared somewhat smaller Thursday, police said a further 19 officers were injured, bringing the total over the past week to 74.

The latest violence came despite appeals from U.K. Prime Minister Boris Johnson, Irish Premier Micheal Martin and U.S. President Joe Biden to calm tensions.