Democrats meet in crucial debate
( BBC ) - The two main Democratic presidential candidates, Hillary Clinton and Barack Obama, have accused each other of negative campaigning in a TV debate.
The two also attacked each other's policies on health care, trade and foreign policy, including the Iraq war.
It is their final face-to-face encounter before next week's crucial primaries in Ohio and Texas.
Mr Obama is regarded as the front-runner, after winning the previous 11 primaries and caucuses.
Analysts say Mrs Clinton needs big wins in both states to stay in the race to choose the Democratic candidate at the national nominating convention in August.
Accusations of dirty tricks and negative campaigning have dogged the past week of the nomination race.
In the opening minutes of the televised debate in Cleveland, Ohio, the two politely but firmly accused each other of spreading misinformation about their policies.
"The charges that Senator Obama's campaign has made regarding fliers and mailers and other information that he has been putting out about my health care plan and my position on Nafta (the North America Free Trade Agreement) have been very disturbing to me," Mrs Clinton said.
Mr Obama retorted that his rival's campaign had "constantly sent out negative attacks on us... We haven't whined about it because I understand that's the nature of these campaigns."
Both insisted they stood for universal healthcare, and that the other's programme would leave some people without cover.
Mr Obama sought to draw a line, however, under the appearance of a controversial photograph of him wearing traditional Somali robes during a visit to Kenya in 2006.
He said he believed Mrs Clinton when she said she did not know where the photo had come from.
Mrs Clinton and Mr Obama went on to say that they would both seek to renegotiate Nafta with Canada and Mexico, under threat of opting out of the seven-year-old pact.
The contest between the two Democratic front-runners has become increasingly heated in recent days.
In a debate last week, Mrs Clinton accused Mr Obama of political plagiarism - a reference to his apparent copying of a supporter's rhetoric.
Mrs Clinton now needs to win a majority of the delegates in the remaining state primaries and caucuses to stay in the race to choose the Democratic candidate for November's presidential election.
Ohio and Texas, both big states, are being seen as must wins for her.
Several polls suggest Mr Obama is gaining ground in both Texas and Ohio. The Illinois senator is leading in Texas for the first time, with 50% compared to 46% for Mrs Clinton, according to a CNN poll.
On Tuesday, Mr Obama won endorsement from a former rival for the Democratic nomination, Senator Christopher Dodd.
On the Republican side, front-runner John McCain has also been campaigning in Ohio, as the party prepares to hold its own primary in the state, also on 4 March.