LYNCHBURG, VIRGINIA (AFP) - Mr Donald Trump declared himself a defender of besieged Christians in a campaign speech to more than 11,000 people on Monday (Jan 18), as the Republican presidential front runner openly courted evangelicals two weeks before the first nomination vote.

The 69-year-old billionaire found a receptive audience at Virginia's Liberty University, an evangelical bastion and a rite of passage for conservative presidential candidates from Mr Ronald Reagan in the 1980s to Mr Ted Cruz, Mr Trump's main Republican rival.

After a Christian rock band warmed up the crowd, the real estate tycoon stressed his ties with evangelicals, who largely vote for conservatives and play a key role in which candidate ultimately wins the party's nomination.

But evangelicals also typically back Republicans that are conservative on social issues, an area of weakness for Mr Trump.

Those in the audience at the Vines Centre were mostly young people, including students who were excused from class, but also included other supporters.

Many attendees at the event, which was open to the public, wore T-shirts and sweatshirts bearing Mr Trump's name.

"We've done great with the evangelicals. The evangelicals have been amazing," the tycoon told the crowd to cheers.

"We're going to protect Christianity. If you look what's going on throughout the world - you look at Syria, where if you're Christian, they're chopping off heads."

Mr Trump, who is known more for his multiple wives, extravagant lifestyle and bombastic rhetoric than piety, kept Christianity at the fore as he spoke at the university founded by Southern Baptist pastor Jerry Falwell.

"You look at the different places, and Christianity, it's under siege," he said. "I'm a Protestant, I'm very proud of it, Presbyterian to be exact, but I'm proud of it, very, very proud."

Mr Trump, who has urged a ban on Muslims entering the United States, upset some by speaking on a US holiday commemorating civil rights leader Martin Luther King.

A handful of students who came to protest were quickly corralled by Secret Service agents behind barricades at a distance from the amphitheatre.

"Dr King is someone who spent more than a decade fighting for equality for all people," said protest organiser Eli McGowan, 21. "Mr Trump, in his words and actions, likes to divide people and ridicule them. He magnifies people's differences. Their racial, ethnic and religious differences."

During his speech, Mr Trump brushed the criticism aside, declaring: "It's an honour to be here, especially on Martin Luther King Day. He was a great man."

Mr Trump, who has never served in public office, again directed his anger and frustration at Washington politicians, who he says are incompetent, as he bolstered his anti-establishment credentials.

"We've been dealing with politicians for so long. All they do is debate, but they never get things done," Mr Trump said.

He also delved into the hot-button issue of immigration, saying "we need powerful borders, strong borders", as he once again pressed for building a wall at the US border with Mexico.

"Two thousand years ago, China built the Great Wall of China. This is a serious wall, and they didn't have Caterpillar tractors," he quipped.

"I have to make it but I have to make it beautiful. Why? Because someday they'll name the wall Trump Wall."

Ms Audrey Bennit, sporting a Trump pin on her sweater, said she was blown away. "I think it was amazing, he talked about a lot of the things I was looking forward to him to talk about," she said.

"Immigration is just a really big problem in this country... He's one of the only ones that talk about protecting Christians, that's very important."

Mr Trump is locked in a tight race with Mr Cruz in Iowa, which on Feb 1 becomes the first state to vote for party nominees.

Mr Cruz, a Texas senator whose father is a Cuban-born evangelical preacher, already enjoys strong support from the evangelical community.

According to polls, nearly two-thirds of evangelical Republicans say a candidate's position on abortion is the most important issue driving their voting decision.

But Mr Trump, who during his political life has been a Democrat and an independent, is only a recent convert to the "pro-life" anti-abortion position.

In recent weeks, he has stressed his own faith as he steps up efforts to reach out to the critical group.