Cambodia’s garment manufacturers were advised to temporarily shut down operations Thursday as tens of thousands of workers at hundreds of factories joined nationwide strikes over wages, disrupting a $5 billion industry that accounts for about 80 percent of the country’s exports. Rallies led by the opposition CNRP also continued to swell, reaching more than 10,000 people in the afternoon, as workers walked off the job and spent the day in Freedom Park, joining the 12th consecutive day of demonstrations calling for the resignation of Prime Minister Hun Sen.