Washington, Jan 20 (IANS): As President-elect Donald Trump stepped into Washington on Thursday for a round of rituals and celebrations in preparation for his swearing-in with a call to unify the country, clashes broke out between his opponents and police --reflecting the mood of the polarised nation.

Several hundred anti-Trump protesters set off fires on the street near a celebration by his supporters at the National Press Club Building and police in riot gear retaliated with pepper spray. Police said that there were no serious injuries or arrests at the incident.

The protesters also pelted eggs at those going to the celebration, which was billed as the "Deploraball" making a joke of the defeated Democratic candidate Hillary Clinton description of Trump supporters as "deplorables".

Trump was not at that celebration, but at a black-tie dinner at the Union Station for his staff and campaign donors. "They are going absolutely crazy," he said there about his opposition.

"We are going to unify the nation," he said earlier at another celebration, a concert at the Lincoln Memorial. "We are going to make America great again for all its people."

About 900,000 people are expected to be at his inauguration on Friday, either as participants or protesters. Homeland Security Secretary Jeh Johnson told the media that 28,000 law enforcement personnel will be deployed.

Trump will begin his presidency at noon on Friday facing opposition unprecedented in modern times, with a sustained attempt to delegitimise his election over allegations of Russian meddling and the fact that he polled fewer popular votes than his Democratic Party rival, Hillary Clinton.

About 70 members of the Congress have announced that they will be boycotting the inauguration ceremonies rallying behind an African American civil rights leader, John Lewis, who asserted that Trump was not a legitimate President.

Indian American Congresswoman Pramila Jayapal, a leftist Democrat, has said that she will join the boycott, but the other four in Congress said they will be at the ceremony. Hillary Clinton is also expected to be there.

An organisation called J20 has threatened to hold protests at the security control points for ticket-holders to enter the inauguration ceremony and elsewhere. Other groups like Occupy Inauguration are also planning protests.

Last week, several anti-Trump protests were held in New York and several cities across the nation.

Trump' faces a virulent onslaught from the media and the cultural elite ahead of his inauguration. Some musicians who had agreed to participation in celebrations on Thursday and Friday were forced to cancel because of the pressures from Trump opponents, who dominate the entertainment that overwhelmingly supported Clinton.

Flying here on Thursday, Trump ditched his plush private plane for an official air force jet.

His first act here was to follow the ritual of laying a wreath at the Arlington National Cemetery where American war veterans are buried.

He is staying overnight at Blair House, the presidential guesthouse. Friday morning he is to go to a church and then visit the White House. From there, he and President barack Obama will then go to the Capitol, the domed building housing Congress, for the swearing-in.

Chief Justice John Roberts will swear-in Trump, who will place his hands on a Bible he used as a child and another that belonged to President Abraham Lincoln.

As the newly minted President he is to walk from there with his family to the White House and occupy the symbol of the presidency.

The Obamas, meanhile, are preparing to leave the mansion for a private residence where they will stay till the younger daughter, Sasha, completes the school year.

Most of their private belongings have already shipped out and while the swearing-in takes place, movers will frenetically work move the last of them and bring in the Trump's things.