US Democratic presidential candidate John Kerry closed in upon Republican candidate George W.Bush in Tuesday's presidential elections after winning the state of California with the largest number of electoral votes of 55, according to projections by major US TV networks.

With projected victories in California and Pennsylvania, which have a combined electoral votes of 76, Kerry has won a total of 188 electoral votes, still nine fewer than that of Bush.

Pennsylvania is one of the three major battleground states in the elections. The other two, Ohio and Florida, with a combined 47electoral votes, remain too close to call.

Kerry has now won in 13 states, while the incumbent Republican President Bush has scored victories in 22 states. To win the presidency, 270 of the 538 electoral votes are needed.

With 50 percent of the nation's precincts reporting, Kerry has won 30,067,287 votes, or 48 percent, while Bush has claimed 31,874,080 votes, or 51 percent, showed the latest nationwide election returns reported by the Associated Press.

American voters started casting their ballots on Tuesday morning, as polling stations were opened at 6 a.m. or 7 a.m. EST (1100 or 1200 GMT) in the states along the east coast. All voting, except in Alaska and Hawaii, were to close at 11 p.m. EST (0400 GMT, Wednesday).

Bush cast his ballot at his hometown of Crawford, Texas, Tuesday before flying to Washington, and Kerry voted in Boston, Massachusetts.

In the general elections, voters will also elect a vice president, 34 senators who account for one-third of the Senate, all the 435 representatives and 11 governors.

Republicans now hold 227 of the 435 House seats while Democratshold 205 seats and have the support of the House's lone independent, Bernie Sanders of Vermont.

In the Senate races, 34 of the 100 seats in the Senate are at stake, 19 held by Republicans and 15 by Democrats. Currently, Republicans enjoy a majority with 51 seats, with 48 of the rest going to Democrats and one to independents.

Republicans took over from Democrats the seat in the key battleground state of South Carolina in the Senate races Tuesday, making it even harder the uphill fight by Democrats for the Senatecontrol.

Exit polls also reported continued Republican control in two other key states of Kentucky and Oklahoma.

Earlier projected results said Republicans also defeated Democrats in Georgia, Ohio, Missouri, New Hampshire and Alabama, while Democrats registered victory in Vermont, Indiana, Connecticut, Illinois and Maryland.

The two sides swapped seats in Illinois and Georgia. In Illinois, Democrat Barack Obama pocketed the Senate seat held by aretiring Republican. He will be the only black member of the Senate.

Democratic Leader Tom Daschle faced a strong challenge in SouthDakota.

According to the country's election system, Americans do not directly choose the president. Instead, after ballots are counted in each state, state representatives, called electors, will vote on the basis of the state tallies in an Electoral College, a system which has been operating since 1788.

It was likely that 58-60 percent of eligibles, or 117.5-121 million voters, would vote at about 200,000 polling stations across the country this year, higher than in 2000 when 54 percent of the electorate, or 105.4 million voters, went to the polls.

Results of the voting were expected late Tuesday night or earlyWednesday morning.

If no candidate receives a majority, the House of Representatives -- one of the two chambers of the US Congress -- must determine the winner from the three candidates who received the most votes in the Electoral College.