BAGHDAD �?Up to 35 officials in the Iraqi Ministry of the Interior ranking as high as general have been arrested over the past three days with some of them accused of quietly working to reconstitute Saddam Hussein’s Baath Party, according to senior security officials in Baghdad.

The arrests, confirmed by officials from the Ministries of the Interior and National Security as well as the prime minister’s office, included four generals, one of whom, Gen. Ahmed Abu Raqeef, is the ministry’s director of internal affairs. The officials also said that the arrests had come at the hand of an elite counterterrorism force that reports directly to the office of Prime Minister Nuri Kamal al-Maliki.

The involvement of the counterterrorism unit speaks to the seriousness of the accusations, and several officials from the Ministries of the Interior and National Security said that some of those arrested were in the early stages of planning a coup.

None of the officials, who spoke on the condition of anonymity because of the delicate nature of the subject, provided details about that allegation.

But the arrests reflect a new set of political challenges for Iraq. Mr. Maliki, who has gained popularity as a strong leader but has few reliable political allies, has scrambled to protect himself from domestic rivals as the domineering influence of the United States, his leading backer, begins to fade.

Rumors of coups, conspiracies and new alliances abound in the Iraqi capital a month before provincial elections. Critics of Mr. Maliki say he has been using arrests to consolidate power.

But senior security officials said there was significant evidence tying those arrested to a wide array of political corruption charges, including affiliation with Al Awda, or the Return, a descendant of the Baath Party, which ruled the country as a dictatorship for 35 years, mostly under Mr. Hussein. Tens of thousands of Iraqis died or were persecuted, including Mr. Maliki, a Shiite Muslim, by the Baath Party. It was outlawed after the American invasion in 2003.

While most members of the Baath Party were Sunni Muslims, as Mr. Hussein was, those arrested were a mix of Sunnis and Shiites, several officials said. It was unclear precisely how many Interior Ministry officials were detained.

A high-ranking Interior Ministry official said those affiliated with Al Awda had paid bribes to other officers to recruit them and huge amounts of money had been found in raids. He said there could be more arrests. Some of those arrested were members of the now-illegal party under Mr. Hussein’s government. Mr. Maliki’s office declined to comment officially. But one Maliki adviser, insisting that he not be named because he was not authorized to speak, said the detainees were involved in “a conspiracy.�?/P>

The Ministry of the Interior is dedicated to Iraq’s internal security, and includes the police forces. The ministry has a history of being heavily infiltrated with Shiite militias, though it has improved considerably over the past two years.

A police officer, who knows several of the detainees but spoke on condition of anonymity for fear of retribution, said they were innocent, longstanding civil servants and had little in common with one another. Those who once belonged to the Baath Party were lower-level members, he said, insisting that the arrests were politically motivated.

Interior Minister Jawad Kadem al-Bolani, who has not been implicated and is out of the country, has his own political ambitions and has been expanding his secular Iraqi Constitutional Party. Iraq is a nation where leadership has often changed by coup, and as next month’s provincial elections approach, worry about violence is increasing. So are accusations about politically charged detentions.

The counterterrorism unit involved in these arrests is alleged to have conducted a raid this summer on the Diyala provincial governor’s office, during which an employee was killed and a provincial council member, one of the few Sunnis Arabs on the council, was arrested.

At a later protest against the arrest, several other Sunni politicians were detained. A number of politicians who follow the Shiite cleric Moktada al-Sadr, and who have set themselves up as political rivals to the prime minister, have also been arrested over the past months and charged with terrorist activities.

Anxieties about the government’s treatment of political enemies were also raised this week as the American military, as part of the recently approved security agreement, turned over to Iraqi custody on Monday 39 senior officials from the Hussein government. Some have been convicted already and others are scheduled to stand trial, the United States military said in a statement.

Saleh al-Mutlaq, a Sunni lawmaker, charged that the safety of the prisoners was in jeopardy. “I think these people are not going to be treated well and that is the American responsibility,�?he said.

Badeei Araf, a lawyer who said he represented 11 of those being turned over, said at least two appeared on the “most wanted�?deck of cards that the United States publicized early in the invasion in 2003. But, he said, neither Ali Hassan al-Majid, known as Chemical Ali and awaiting execution, nor Tariq Aziz, the public face of the Hussein government, were among those transferred.

On Wednesday morning, a bomb planted in a minibus exploded near a parking lot belonging to an Iraqi traffic police station in the Nadha neighborhood of Baghdad, killing up to 18 people and injuring scores, police officials said. Some Iraqi officials put the death toll at eight.

A small blast in a market of barbershops and butchers drew people out of their homes before the minibus exploded. The attack appeared to be against the police station; at least three of those killed were police officers.

Also on Wednesday morning, Gordon Brown, the prime minister of Britain, made a surprise appearance at a news conference in Baghdad with Mr. Maliki, where he confirmed that British forces would end their operations in Iraq by the end of May and would withdraw from the country by the end of June.