Irish police were out in force Friday night in Dublin to prevent a repeat of rioting blamed on far-right agitators that erupted after a knife attack outside a school that injured three children. Officers made sporadic arrests after darkness fell as youths began to congregate on O’Connell Street, one of the city’s most famous thoroughfares that was the scene of violence, vehicle fires and looting the previous night. But the situation was generally stable, with the country’s police force — known as Garda Siochana — posting on social media that “Dublin city centre is open for normal business”. “We have an enhanced policing plan in place this evening,” it said, adding that people were welcome there over the coming weekend.