AMMAN, Jordan—Scores of Jordanian protesters demanding democratic changes from their king burned an American flag Friday, denouncing what they called attempts by Washington to interfere in the reform movement.

About 300 protesters, mostly leftists and nationalists, chanted, “America is the head of the snake,” as the flag burned at the protest in the capital, Amman.

It was a rare burst of anti-U.S. sentiment in the pro-reform movement that has been holding rallies for months in Jordan, though at a smaller scale than the protests that shook Egypt, Tunisia and other Arab nations.

Protesters accused the United States of trying to co-opt their movement. They pointed to efforts by U.S. diplomats to meet and advise pro-democracy activists and to comments by President Barack Obama and Secretary of State Hillary Clinton praising reform efforts by Jordan, whose king is a close ally of Washington.

“We don’t need Washington’s help and we don’t take orders from you,” said 28-year-old activist Mohannad Safiin.

“These are our protests. Keep out of our business. For years, the U.S. government supported these same Arab regimes which have killed our own people,” he said.

Friday’s numbers were small compared to hundreds and even thousands participating in six months of mainly peaceful protests here demanding greater political say, lower food prices and new parliamentary elections.

Marching past the Al-Husseini mosque in downtown Amman, they demanded the dismissal of Prime Minister Marouf al-Bakhit, a tough former army general viewed as incapable of enacting needed changes.

“We have a different vision of what we want from reform,” said Ibrahim Alloush, an independent activist.

“We don’t want just a change of faces,” a reference to King Abdullah II’s habitual reshuffles of prime ministers and Cabinets.

Abdullah has responded to protests with a pledge to consider allowing voters to choose the prime minister and the Cabinet. Currently they are appointed by the king.

Alloush said protesters also do not merely want the transfer of some of the king’s prerogatives given to somebody else and instead want a real functioning democratic structure to emerge following free and fair parliamentary elections.

Protesters also called for press freedom, after police attacks wounded at least 16 journalists and photographers among dozens of others last week during an attempt to set up a protest camp in central Amman.

On Thursday, Abdullah criticized the violence and said the government and police must allow journalists to cover political events and guarantee their safety.

Some protesters held up signs depicting a menacing-looking anti-riot policeman armed with wooden baton and shield. The caption read: “This is where your dignity ends.”