Iranian opposition groups have called for a new round of street demonstrations Wednesday to coincide with the inauguration of President Mahmoud Ahmadinejad for a second term.

The country's reform movement says it plans to demonstrate outside parliament in Tehran, to protest the swearing-in of Mr. Ahmadinejad.

A massive security presence is expected outside parliament and in other areas of the capital during the inauguration ceremony.

On Tuesday, Iranian reformist and former presidential candidate Mehdi Karroubi said protests against the June re-election of Mr. Ahmadinejad will continue. Karroubi told the Spanish newspaper El Pais that he and leading opposition figure Mir Hossein Mousavi will never work with the Ahmadinejad government.

The two former presidential candidates were absent Monday at a ceremony during which Iran's supreme leader formally endorsed Mr. Ahmadinejad's second term.

In Washington, White House Press Secretary Robert Gibbs said he does not expect U.S. President Barack Obama to send a letter of congratulations to Mr. Ahmadinejad. When a reporter asked Gibbs if the White House recognizes Mr. Ahmadinejad's presidency, the White House spokesman responded that Mr. Ahmadinejad is "the elected leader."

On Thursday, a mass trial is scheduled to resume for about 100 prominent reform activists and political figures accused of trying to topple Iran's government.

Hundreds of activists who claim the June 12 presidential election was a fraud have been arrested in street protests, which have been compared to the unrest that led to the 1979 Islamic Revolution.

Some information for this report was provided by AFP, AP and Reuters.