Polls closed in some U.S. states on Tuesday, with indications that the Democrats could wrest control of the House of Representatives away from President George W. Bush's Republicans, amid voters' calls for a new policy in Iraq.

Opinion polls showed that for the first time in 12 years Democrats were favored by voters to be at the helm of the House again.

All 435 seats in the House are up for election. Democrats need a net gain of 15 seats to recapture control of the House in this year's elections, after they have been in the minority since 1994.

Democrats have fiercely fought Republicans for control of the Senate and they need to grab another six seats to have the majority that they possessed in 2001-2002.

In the Senate, members are elected for six-year terms, with one third of the seats up for election every two years. Currently, the Republican Party holds a majority of 55 seats against the Democrats' 44 seats, and there is one Democratic-leaning Independent. Of those 33 seats up for election, 17 were held by Democrats, 15 by Republicans and one by Independents.

The United States holds federal elections on the first Tuesday after the first Monday in November of every even-numbered year, in which all House members and 33 or 34 of the 100 Senate members will be elected, as well as state legislators and some state governors.

While presidential elections take place every four years, those elections for Congress that do not coincide with presidential races and occur midway through a presidential term are called midterm elections.

Source: Xinhua