HONG KONG — Malaysia's government announced plans to repeal a colonial-era speech law used in the past to quiet political dissent, but provided few details of the new legislation, in a move that was greeted by political observers Thursday with cautious optimism. Prime Minister Najib Razak said the current Sedition Act, enacted in 1948 when the Malaysia was under British rule, “represents a bygone era in our country” and will be replaced with new laws he called the National Harmony Act, according to a statement released late Wednesday. The new legislation will aim to protect freedom of speech while preventing the incitement of religious or ethnic hatred, he said. Critics of the Sedition Act have complained that the government has used the law as a weapon against political opponents. In 2009, Karpal Singh, the chairman of the opposition Democratic Action Party, was charged with sedition after being accused of insulting the sultan of Perak state. Rights activists welcomed Najib's announcement, but held out full endorsement until details of the new free-speech laws are known. “Until the Malaysian people see the draft of the National Harmony Act and can make an informed comparison of the current and proposed future law, the jury will still be out, waiting to render a decision,” said Phil Robertson, the deputy Asia director for Human Rights Watch. Najib, who took office in April 2009, has promised to strengthen civil liberties in Malaysia. Earlier this year the government installed new laws that limit how long the police can hold suspects without trial. Critics, however, point to the government's new law regulating public assembly — the Peaceful Assembly Act — as an example of revisions that have not improved rights across Malaysia. The law requires organizers of protests to notify the authorities 10 days in advance of the demonstration unless they are meeting in “designated places.” Additionally, the police can set conditions on demonstrations, like date, time and place. In April tens of thousands of people took to the streets in Kuala Lumpur to call for electoral reforms, a protest that the police had not authorized under the rules. Nearly 400 people were arrested, and the opposition leader, Anwar Ibrahim, and two of his colleagues were charged under the law. — Agencies