BEIRUT, Lebanon — With his adversaries boycotting the ceremony and a vast cheap watches deployment of police officers standing guard outside, Mahmoud Ahmadinejad was sworn into office on Wednesday for a second term as president, almost two months after an election that divided the nation and set off Iran’s deepest crisis since the Islamic Revolution 30 years ago. There were scattered protests in the streets around the Parliament building in replica watchesTehran, where the ceremony took place. But with thousands of riot police officers and Basij militia members patrolling the capital, the million-strong rally called for by the opposition failed to materialize. The inauguration ceremony itself exposed deep rifts in Iran’s ruling elite. Many seats were empty, with most of Parliament’s reform faction boycotting the event, according to Parlamaan News, a reformist Web site. Several reformists who did attend walked out as the president began his speech. Leading opposition figures, including the Cartier watches presidential candidate Mir Hussein Moussavi and the former presidents Ali Akbar Hashemi Rafsanjani and Mohammad Khatami, also stayed away. Subway stations and shops around the Parliament building were closed, in a sign of concern about possible violence. Mr. Ahmadinejad must form a cabinet in the next two weeks, and his choices will signal much about the direction his second term will take. He is likely to face rising dissent from within his own conservative camp, as he did last month during a heated fracas over his first appointments. His government will also be struggling to put down a defiant opposition movement that maintains that his landslide Chopard watches June 12 re-election was rigged, and has continued to mount street protests. That task may grow harder as the school year and athletic seasons start next month, providing new opportunities for mass rallies. But for all the challenges facing him, Mr. Ahmadinejad remains firmly in control, with the clear support of Iran’s supreme leader, Ayatollah Ali Khamenei, who formally endorsed his presidency in a religious ceremony on Monday. He has the backing of a large parliamentary Bvlgari watches majority, the powerful Revolutionary Guard, and the silence — if not the open support — of Iran’s clerical establishment. “I, as the president of the Islamic republic of Iran, swear before the holy Koran and the Iranian nation and God to be the guardian of the official religion, the Islamic republic and the Constitution,” Mr. Ahmadinejad intoned as he took the oath of office. A brief film shown before the ceremony highlighted Iran’s scientific achievements, including the Jaeger LeCoultre watches cloning of sheep and the launching of the Omid satellite. In a brief inauguration speech, Mr. Ahmadinejad made clear that he viewed his re-election as a mandate to move aggressively on a variety of issues, including plans to rebuild Iran’s troubled economy and reform the subsidies system. He also spoke contemptuously about the Western countries that had refused to congratulate him on his election victory. “No one in Iran is waiting for your congratulations,” he said. “The people of Iran care neither for your grimaces nor for your congratulations and smiles.” Secretary of Tissot watches State Hillary Rodham Clinton, asked about the inauguration during a news conference in Kenya, where she began a seven-nation Africa tour, said, “Engagement is still on the table with the Iranians,” though that does not mean the United States is not considering other options. She added a word of admiration for Iran’s opposition movement, saying, “We appreciate and admire the continuing resistance.” The opposition movement persists, but in recent days the authorities have stepped up efforts to intimidate and silence it. On Tuesday, Mir Hamid Hassanzadeh, the director of Mr. Moussavi’s Web site, was arrested, Iranian news agencies reported. Meanwhile, a mass trial of more than 100 reformists is under way. As the trial opened last weekend, some senior opposition figures were shown on state television delivering humiliating “confessions” in which they said there had been no election fraud, and detailing foreign-led plots to bring down the Iranian government with a Audemars Piguet watches “velvet” revolution. Such confessions are familiar from earlier trials, and defendants and human rights groups say they are almost always obtained through torture. Prosecutors have warned that anyone questioning the legitimacy of the trial — as many opposition figures have — could in turn be prosecuted. Some senior lawmakers have hinted in recent days that Mr. Moussavi and other opposition leaders could be arrested soon, though it is impossible to tell if that is only a scare tactic. But the opposition does not seem to have been cowed. In recent weeks, as news emerged of protesters who died in prison after being arrested, Mr. Moussavi and others spoke out more forcefully than ever before, accusing the government of savage and criminal acts. The anger spread to some prominent conservatives, prompting a number of conciliatory efforts by the government, including the release of more than 140 prisoners and the closing — at the personal order of Iran’s Mont Blanc watches supreme leader — of a detention center.