Thousands marched in El Salvador on Sunday to air a range of grievances against President Nayib Bukele, from adopting bitcoin as legal tender to firing Supreme Court judges, which has been viewed by his critics as a power grab. At least 4,000 people took the streets in San Salvador, according to estimates by local media. Some carried banners and signs rejecting bitcoin, which officially became legal tender in the Central American country in September. Others opposed the potential for Bukele to seek a second consecutive term.Near the capital's main square, protesters set fire to a doll bearing the likeness of the 40-year-old president.Last month, Bukele proclaimed himself "dictator" of El Salvador on his Twitter account, in an apparent joke amid concerns about his increasing concentration of power. In May, a Congress dominated for the first time by Bukele's New Ideas party voted to fire the judges on the constitutional panel of the Supreme Court, among the most senior jurists in the country. Replacements seen as friendly to Bukele were then swiftly voted in, which generated harsh criticism from the United States as well as top international rights groups.Bukele, a seasoned and often provocative user of social media, dismissed Sunday's protests on Twitter, saying: "The march is a failure and they know it."