KYIV—Belarusian police searched the offices and homes of journalists and human rights activists for the third successive day on Friday, extending what rights activists say is a new crackdown on opponents of President Alexander Lukashenko. The Poland-based Nexta Live channel said the office of U.S. broadcaster Radio Liberty in the capital Minsk was among those raided. Belarusian human rights organization Viasna-96 reported that two Radio Liberty journalists had been detained. Belarusian security officials were not immediately available for comment. The authorities have shut down a number of non-state media outlets and human rights groups since protests began last August against a presidential election which the opposition say was rigged. Lukashenko, in power since 1994, denies electoral fraud. Police officers went on Friday to the homes of a journalist from Polish TV channel Belsat and those of several local reporters, Viasna-96 reported. On Wednesday and Thursday, security officials conducted searches in …