Democratic presidential candidates Hillary Clinton and Barack Obama are seeking crucial votes in Indiana and North Carolina, where primary elections will be held Tuesday. Meanwhile, Democrats in the in the small Pacific island territory of Guam made their choice between the two candidates in Saturday's party caucuses. VOA's Kent Klein reports from Washington.

Public opinion polls show that Barack Obama's once-significant lead over Hillary Clinton in the Southern state of North Carolina has dwindled in the past few days. Obama spent part of the past week criticizing his former church pastor, the Reverend Jeremiah Wright, who had made a series of controversial comments that considered harmful to Obama's campaign.

Obama and Clinton criticized each other Saturday over their proposals for fighting rising gasoline prices. Clinton and the presumptive Republican nominee, John McCain, want to suspend federal taxes on gasoline this summer.

In Gastonia, North Carolina, Clinton attacked Obama for opposing her plan. "I understand my opponent disagrees with me. He does not want to give you a gas holiday. He does not want to go after the oil companies. He would not vote against them with the 2005 Dick Cheney energy bill, and I did," she said.

Before becoming U.S. Vice President, Dick Cheney had been an officer for the Halliburton oilfield technology company.

Obama campaigned in the Central state of Indiana, where polls show a very close race. In the state capital, Indianapolis, he charged that Clinton's proposal to lift the gas tax is an election-year gimmick, and that she is allied with the oil companies. "Senator Clinton had to send out a surrogate to speak on behalf of this plan, and all she could find was, get this, a lobbyist for Shell Oil, to explain how this was going to be good for consumers. It is a Shell game," he said.

The western Pacific island of Guam held Democratic Party caucuses on Saturday. Its residents cannot vote in the presidential election in November, but the tiny U.S. territory will send four delegates to the party convention. Neither candidate campaigned there.

As the primary election season nears its end, Obama leads in overall pledged delegates, the popular vote and the number of states won. But both he and Clinton need the support of superdelegates to clinch their party's nomination.

Superdelegates are Democratic Party officials and elected office holders who will be allowed to vote at the party convention.