Bahrain's king ousted four cabinet members Saturday as a prominent opposition leader returned from exile and urged the country's rulers to back up reform promises with action. Thousands of demonstrators pressed their demands for change by marching on government buildings in the capital.

Two members of the royal family were among the replaced cabinet members, a possible nod to protesters' complaints that the ruling house of Al Khalifa holds too much control over state levers of power.

Bahrain's prime minister — the king's uncle, whose more than four decades in power has made him a focus of protesters' calls for reform — remains in his post.

Meanwhile, the return from self-imposed exile of Hassan Mushaima, a senior Shiite figure, could mark a new phase for an anti-government movement in the tiny Persian Gulf nation that is a strategically important American ally. He heads a Shiite group known as Haq, which is considered more hard-line than the main Shiite political bloc that has helped drive two weeks of protests.

He was embraced and kissed at the airport by supporters as he returned Saturday from several months of voluntary exile in London. His speaking appearance hours later, preceded by bursts of fireworks, electrified an already enthusiastic crowd packed into Pearl Square, the center of demonstrations.

Mushaima, who had been among a group of Shiite activists previously accused of plotting to overthrow Bahrain's rulers, called on the government to be more responsive to protesters' demands for far-reaching political reforms.

"Dialogue ... is not enough. Promising is not enough. We have to see something on the ground," he told reporters. Bahrain's rulers "have promised before but they did not do anything for the nation of Bahrain," he said.

The Bahraini opposition appears divided over whether to demand an end to the Sunni monarchy or offer it a chance to remain in exchange for handing powers to the elected parliament.

Mushaima did not call directly for the removal of the monarchy, but insisted any changes should grant more power to the people. Asked if he hoped to lead the protest movement, he said: "I'm always saying to the people, 'I'm your servant.'"

His return to Bahrain was briefly delayed when his passport was confiscated during a stopover in Beirut on an Interpol warrant Tuesday. But Bahraini authorities suspended the trial this week, and Lebanon returned his passport Friday.

Daily anti-government protests in Bahrain erupted two weeks ago, as part of a wave of political unrest that is spreading across the Arab world. The movement in Bahrain is led by Shiites who account for about 70 percent of the country's 525,000 people, but have long complained of systematic discrimination and other abuses by the Sunni dynasty that has ruled for more than two centuries.

On Saturday, thousands of protesters carrying red-and-white national flags and chanting anti-government slogans marched from the landmark Pearl Square into the Bahraini capital's government and business district. A few police deployed near the state compound that includes the prime minister's office watched as the crowd passed but did nothing to intervene.

One marcher carried a portrait of Prime Minister Sheik Khalifa bin Salman Al Khalifa crossed out with a red "X."

The march appeared designed to carry demonstrators' demands into the heart of official Bahrain, where a branch of Starbucks and shiny office towers housing regional bank headquarters stand testament to the country's prosperity.

Many Shiites complain that too little of the nation's oil wealth trickles down to their neighborhoods and villages, and that they have little chance of securing well-paying government jobs.

The king addressed economic concerns head on in a royal decree outlined Saturday. Along with the cabinet reshuffle, King Hamad bin Isa Al Khalifa ordered the government to cut by 25 percent what recipients of state loans are required to pay each month. The state-run Bahrain News Agency said the measure would benefit more than 35,000 families. It was unclear if the overall loan amount would also be reduced.

The decree called for the removal of the ministers of housing, electricity and water, health, and cabinet affairs. The minister of labor was also replaced, but he will remain in the cabinet as the new housing minister.

Bahrain is the first Gulf state to be thrown into turmoil by the Arab world's wave of change. The unrest is highly significant for Washington because Bahrain is home to the U.S. Navy's 5th Fleet, the Pentagon's main counterweight against Iran's widening military ambitions.