Election officials say Malaysia's ruling coalition has won a simple majority in parliamentary polls, extending its 56-year rule after a tough fight with a strengthened opposition alliance.
Preliminary tallies show Prime Minister Najib Razak's National Front coalition capturing 112 of Malaysia's 222 legislative seats, and 57 for the opposition's three-party alliance.
Hours after the polls closed on Sunday, opposition leader Anwar Ibrahim, in a message posted on Twitter, said his coalition will not accept the results until elections officials explain "alleged instances of fraud." He did not offer details, and it was unclear what effect formal appeals might have on the outcome.
More than 10 million people cast ballots for a record turnout of about 80 percent.
The opposition campaign centered on allegations of ruling party arrogance, abuse of public funds and racial discrimination by the government against the country's sizeable ethnic Chinese population.
The win marks National Front's 13th consecutive victory in general elections since Malaysia's independence from Britain in 1957.
The opposition retained control of northern Penang state, one of Malaysia's wealthiest territories, and it remained strong in the capital, Kuala Lumpur.
Numerous rumors of cheating plagued the polls, including the use of ink to mark voters that critics said could be easily washed off. There also were complaints of foreigners being flown into the country to cast ballots.