WATCH: Angry walkout by Sanders supporters

PHILADELPHIA - So much for party unity.

Hundreds of supporters of Vermont Sen. Bernie Sanders walked out of the Democratic National Convention on Tuesday evening, timing their angry protest to the official nomination of Hillary Clinton.

The exodus came moments after a surprise appearance at the convention site by Jill Stein, the Green Party's presidential candidate. Stein was surrounded quickly by a chanting crowd off the convention floor at the Wells Fargo Center, but also was the target of barbs and insults by delegates who backed both Clinton and Sanders.

Demonstrators abandoned their seats as the convention floor erupted in a celebration of Clinton's nomination, which had been supported minutes earlier in a roll-call speech by Sanders.

Sign-waving protesters flowed through the concourse, then joined in a minutes-long stream that poured out of the building. Many marched into a nearby media tent, which was then sealed off temporarily by Philadelphia and Pennsylvania State police.

"Show me what democracy looks like," some shouted. "This is what democracy looks like," answered the moving line of protesters.

A smiling Clinton supporter joined their ranks, but he was using the arrow on a campaign sign to point the protesters toward the doors.

A New Jersey delegate, Derel Stroud of Ocean Township, urged the demonstrators to turn back, saying Stein lacked the organization and support to beat Republican presidential candidate Donald Trump.

"You have a better chance of seeing Jesus rolling dice outside the 7-Eleven," shouted Stroud, a Sanders supporter who said he would back Clinton. He urged the dissidents to "trust Bernie and vote Hillary."

But Stroud, who left the convention "to defuse" tensions among the protesters, did not sound enthusiastic.

"Inside it's the land of the phonies," he said of the Democratic gathering.

The scene outside the arena was peaceful, but demonstrators expressed anger and frustration, claiming Clinton won due to unfair tactics and voter fraud. Some wept.

"It's a travesty," said Matthew Rock, a Sanders delegate from Oregon, who stood with his arms outstretched outside the media tent. He'd written "rigged" on one arm, "stolen" on the other.

Next to him, Sanders supporter Yamina Roland of California covered her mouth with red tape and held a handwritten sign on a notebook: "I am a silenced delegate."

A short time earlier, Stein's appearance had sparked a heated confrontation between people who embraced the Green Party candidate and others who called her a "vulture."

"Bernie's a politician but he's been honest with us," said Vincent Venditti, a Sanders delegate from Georgia who insisted Clinton could not win the November election. "He's done what he said he would do, but he does not control us."

Some people in the crowd expressed a mix of unhappiness and uncertainty.

Katy Roemer and Martha Kuhl, both Sanders supporters from California and member of a nurses' union, dismissed the convention as a "Clinton-fest" that had not addressed issues of importance to them.

"For the first time, there was a candidate speaking to the issues that I care about," Roemer said of Sanders.

"We're going to have to look at whether or not Clinton is going to listen," Kuhl said.

Shannon Eblen contributed to this report. Jim Walsh; (856) 486-2646; jwalsh@gannettnj.com