KIEV, Ukraine (AP) – Prime Minister Viktor Yanukovych took the lead Monday in Ukraine’s presidential election with about 46 percent of the vote, according to partial results, but that was not enough to avoid a runoff next month after balloting marred by fears of violence and charges of election fraud.

With nearly 50 percent of the precincts counted from Sunday’s vote, the main challenger, opposition leader Viktor Yushchenko, had 33.59 percent of votes, the Central Elections Commission said.

Yanukovych started the count with an overwhelming 67 percent lead, but his margin was dwindling with every incremental announcement of results. The latest reports showed Yanukovych garnering 46.20 percent. An array of exit polls put the two top candidates within a few percentage points of each other.

, and both of them below the 50 percent needed to avoid a Nov. 21 runoff.

Official results that differed sharply from the polls could inflame tensions, which were already high in the former Soviet republic after weeks of opposition claims that officials planned wide-scale vote fraud.

Yushchenko, in a live television broadcast, said early Monday that a count by his campaign observers showed him with just over than 50 percent of the vote, with 10,800 of the 33,000 precincts tallied. He characterized it as “a victory for the democratic forces.”

But Yanukovych’s campaign announced that its count of 50 percent of votes showed the prime minister with 41.2 percent, while Yushchenko has garnered 38.7 percent.

The Central Elections Commission building was encircled by metal barriers and dozens of policemen deployed inside the compound were backed by water cannons and armored vehicles.

Security forces also beefed up protection of the building of Ukraine’s state-run TV and other key facilities in Kiev late Sunday, the Interfax news agency quoted Anatoly Prisyazhnyk, a police spokesman, as saying.

The vote was seen as a key test of democracy in this nation of 48 million people a little smaller in size than Texas and as an indicator of what direction Ukrainians will choose for their nation, which has cultivated ties with the West and neighboring Russia. Ukraine also has shown strong economic growth, primarily in heavy industry, after years of post-Soviet economic chaos.

According to the preliminary results, the vote was split along clearly regional lines, with Yanukovych getting strong support in eastern regions and the Russian-dominated Crimea while Yushchenko overwhelmingly dominated in the west.

Yanukovych is seen by many as likely to push for closer relations with Russia, which borders Ukraine to the east. The eastern parts of Ukraine are heavily populated by Russian-speakers.

An exit poll conducted by the Kiev International Institute for Sociology and the Razumkov Center for Political and Economic Research had given Yushchenko a comfortable lead over Yanukovych, with a 45-37 percent margin, the Unian news agency said.

But another poll, by the Social Monitoring and Socis groups, showed Yanukovych leading with 43 percent of the vote to Yushchenko’s 39 percent, Unian said. A preliminary version of that poll had Yushchenko with a 2-percentage-point lead.

The polls, each based on questioning of 20,000-25,000 voters nationwide, were conducted by different methods. The one showing Yushchenko winning asked respondents fill out forms anonymously, while the other was done by face-to-face interviews.

The discrepancy could indicate concern by respondents over identifying themselves as opposition supporters. Yanukovych has the backing of incumbent President Leonid Kuchma, who has clamped down on opposition.

Both polls were sponsored by the U.S., Canadian and British embassies as well as U.S. National Endowment for Democracy.

Earlier, the ITAR-Tass news agency reported Yanukovych as leading in the vote count, citing Gennady Korzh of the Yanukovych election staff press service and exit poll information from mid-afternoon.

To win outright, a candidate needed more than 50 percent of the vote. If needed, and a runoff is to be held in three weeks.

The ballot had a total of 24 candidates. Final turnout was 76 percent, the Central Election Commission said.

The vote followed weeks of high-tension campaigning, in which the opposition complained of widespread abuse and interference by officials. The opposition also complained of abuses during Sunday’s voting.

Yanukovych and supporters, in turn, accused the opposition of aiming to foment mass disorder in the country.

“The key issue is to preserve peace in the country,” said Serhiy Tyhypko, Yanukovych’s campaign chief.

Late Sunday, a group of armed men stormed three polling stations in the eastern city of Kirovohrad and seized ballot boxes, the Interfax news agency reported. They also fired several shots in the air.

The United States has warned it may take punitive actions if the voting is marred by irregularities in Ukraine, which has a brigade of troops in Iraq. Ukraine has been one of the top recipients of U.S. aid.

Both candidates have promised to push for even more growth in the country where millions still live in poverty. Despite a 70 percent raise in September, monthly pensions still average only about $52.

Yanukovych’s detractors claim he will continue the crony capitalism they say was rampant under Kuchma and allowed a relative few to become extremely wealthy. They also fear Yanukovych will, like Kuchma, try to intimidate the opposition and independent media.