BRUSSELS—Belgium brought in new restrictions on Friday such as the closure of nightclubs and an earlier end for bars and restaurants to reduce social contact amid a fourth wave of COVID-19 infections. The new measures, which enter force on Saturday for three weeks, come just a week after a previous package of coronavirus restrictions, including enforcing wider use of masks and more working from home. Under the new rules, Christmas markets, cultural sites, bars, and restaurants will have to close at 11 p.m., with a maximum of six people per table. Private parties and gatherings are also banned, unless they are for weddings or funerals. In addition, Belgians will have to do shopping on their own. The country’s health ministers will meet on Saturday to discuss accelerating the roll-out of vaccine booster doses. Primary school teachers and childcare staff may be given priority.