'Smoke bomb' thrown in White House by Occupy protesters

An apparent smoke bomb was thrown over the fence of the White House as hundreds of Occupy protesters massed outside the gates.

The crowds were dispersed Tuesday night, and US Secret Service spokesman George Ogilvie says there were no arrests in the incident.

However, people inside the White House were being prevented from exiting on the Pennsylvania Avenue side of the building as the situation was being resolved.

Ogilvie says there were 1,000 to 1,500 protesters at one point. He said something appearing to be a smoke bomb was thrown over the fence and that the device was being removed.

The protesters affiliated with the Occupy Wall Street movement converged on the West Lawn of the Capitol to decry the influence of corporate money in politics and voice myriad other grievances.

Organizers had touted the rally, known as Occupy Congress, as the largest national gathering of Occupy protesters to date and secured a permit that would have allowed up to 10,000 people to participate.

The Occupy movement began in September when protesters pitched tents in a lower Manhattan park. The movement has since spread to dozens of cities, including Washington. While many cities have moved to evict the protesters, the National Park Service has allowed encampments to remain in two public squares near the White House.

The protest comes amid numerous polls that show 84 percent of Americans disapprove of the job Congress is doing, near an all-time low.

The Occupy movement includes activists who want to change government from within and anarchists who oppose all government. Tension between the two camps was evident at Tuesday's gathering, where some taunted police while others participated in earnest group discussions about how to influence their elected representatives.

Obama leads against potential Republican nominees

US President Barack Obama has increasingly gained in his popularity rating and leading the odds against two leading potential Republican challengers in the 2012 presidential elections, latest opinion polls said.

"President Barack Obama's numbers are on the rise in two important indicators of his reelection chances, according to a new national survey," the CNN said.

The poll indicated Obama's margins have increased against five possible Republican presidential challengers in hypothetical general election matchups and his approval rating is up five points since mid-November.

According to the poll, Obama leads leading Republican candidate Mitt Romney 52 per cent - 45 per cent in a possible 2012 showdown.

Romney, who's making his second bid for the GOP nomination, held a 51 per cent - 47 per cent margin over the president in last month's survey, CNN said.

Obama also leads against other top Republican candidates, Newt Gingrich, Rick Perry, Ron Paul and Michele Bachmann.

"Bill Clinton and George W Bush - the last two presidents who won reelection - had roughly this same amount of support in December of the year before the election, but so did Bush's father in December of 1991. He ended up losing in the general election," says CNN.

However, the White House said Obama is right now focused addressing key challenges facing the country.

"I will simply say that polls go up and down. We live in a very challenging political environment and, more importantly, in a continuingly challenging economic environment," White House Press Secretary, Jay Carney said.

"This President's focused on the challenging economic environment, and admittedly, in focusing on that, he has to content with the challenging political environment," the White House Press Secretary, Jay Carney said.

"But right now he is committed to working with Congress and doing the things he can do outside of Congress to grow the economy and help it create jobs.

"I think that in these last several months that focus has been pretty clear. He is going to continue that focus. And the impact that has on polls remains to be seen. But it is his primary focus as President," Carney told reporters at his daily news conference.