As Haiti’s carnival drums prepare to kick off in this weekend’s pre-Lenten celebrations, a different kind of rumbling has attracted the attention of the international community.

So concerned are Haiti’s foreign friends about looming political tensions that the U.S. Ambassador to the United Nations, Susan Rice, ended a four-day visit to the earthquake-ravaged nation calling on its political leaders to stop the fighting.

“Haiti’s executive and legislative branches,’’ Rice said, “need to rise above their interests and work together in the spirit of compromise to overcome their common challenges.”

Rice led a 15-member delegation of the U.N. Security Council on a visit to Haiti this week. They left on Thursday after field trips to the police academy, a tent city, cholera treatment facility and new industrial park in the north. They also met with President Michel Martelly, Prime Minister Garry Conille, parliamentarians and business leaders.

“The president and prime minister have prioritized investments to create jobs to build a brighter future,” she told reporters. “But we also understand that improvements in the rule of law, in institution building, fighting corruption and removing other barriers to growth are key to attracting and retaining the quality and quantity of investments that Haiti needs.”

But leaders working together in perpetual turmoil in Haiti remains challenging as fears of a deepening post-carnival political crisis loom.

“From what we heard, there is a risk of political confrontation,” Ambassador Philip Parham, the United Kingdom’s deputy permanent representative, told The Miami Herald in a telephone interview from New York. “Some people think it is really significant.”

On Friday, the National Palace issued a statement saying “trouble makers” near the Champ de Mars attacked the president’s motorcade. Haitian radio reported that Martelly, who was on foot, was hit by a rock but not seriously injured.

Parham said it’s important for Haitians to quickly find a way to resolve their differences.

“One vital ingredient in moving forward is going to be clear and inclusive leadership from the top,’’ he said.

Haiti’s political stalemate has been ongoing, but has hit a fever pitch after Conille announced plans to audit $300 million in contracts awarded by his predecessor during the 18-month emergency period after the earthquake. The contracts were financed by a Venezuelan fund.

Then this week, Conille ordered his ministers to cooperate with a Senate commission that is investigating the nationalities of several members of the government including himself, Martelly and several ministers. Some lawmakers have charged they hold foreign passports, which would make them ineligible to govern under Haiti’s Constitution. All have denied the accusations.

Conille’s directive, however, flew in the face of a decision by Martelly that the commission lacked authority.

On Thursday, the prime minister was the only one who appeared at the parliament with his passports. That same day, the leading opposition party in the parliament issued a statement distancing itself from Martelly and his government, and publicly rebuking its leaders in the Senate, Joseph Lambert. The opposition has accused Lambert, who chairs the commission, of supporting Martelly.