AMSTERDAM, July 9 (Reuters) - The Dutch government reimposed COVID-19 curbs on nightclubs, music festivals and restaurants on Friday in an effort to halt a surge in COVID-19 infections among young adults. The Netherlands lifted most lockdown measures on June 26, as cases were falling. Roughly two-thirds of the population has had at least one vaccination shot. But, with bars, restaurants and nightclubs open again, new infections have risen at the fastest pace in months, with nearly 7,000 cases reported over the 24-hours through to Friday morning. That compared with fewer than 1,000 a week earlier. "Partly because of the Delta variant, infections are rising very fast," Prime Minister Mark Rutte said. "Our goal is to rein in the virus, protect the vulnerable groups and make sure the healthcare system is not overrun." The measures included earlier closing of cafes and restaurants and a return to social distancing and fixed seating for diners or concert-goers. All dance venues and nightclubs will be closed because it will be impossible to ensure social distancing. Festivals spread over several days would be cancelled and large public gatherings restricted to smaller groups, Rutte said. The curbs would go into effect at 0500 GMT on Saturday and remain until Aug. 14, the government said. So far, the new spike in infections has not led to an increase of COVID-19 patients in hospitals. But health minister Hugo de Jonge said the current low level of hospital admissions could be threatened by an "unprecedented" increase in infections. Around three-quarters of new cases in the Netherlands are occurring among young people and more than half are of the more infectious Delta variant, the health minister said this week.