Armed fighters claiming allegiance to Abu Musab Zarqawi took to the streets of a western Iraqi provincial capital Thursday in a fleeting show aimed at intimidating Iraqi Sunni Arab leaders taking part in dialogue with U.S. Marines in a stronghold of the insurgency, provincial officials, residents and other witnesses said.

The scene -- lean figures, many in masks and dark tracksuits lugging shoulder-mounted rocket launchers or wielding AK-47 assault rifles -- reinforced what the U.S. military has acknowledged is the strong insurgent presence in the Euphrates River cities and towns of Anbar province, an overwhelmingly Sunni area near the Syrian border. The appearance of the fighters dismayed many of the residents of Ramadi, the war-blighted provincial capital.

"We are tired of the present situation," said Ahmed Hassan, a 24-year-old dentistry student at Anbar University. "The Zarqawi group has become like a worm inside our guts. We are scared of informing on them and cannot deter them or object to what they are doing. Their only language is that of killing and death, and we fear that."

The armed fighters on the streets left statements in the name of Zarqawi's group, saying their show of force was in response to negotiations between the "Sunni midgets and the stooges of the occupation forces." The statements contained pledges to kill each Sunni leader participating.

The U.S. military, which maintains Marine bases and thousands of troops on the outskirts of Ramadi, denied the accounts of unrest, saying that the city was largely calm Thursday and that insurgents were manipulating the news media. "Today I witnessed inaccurate reporting, use of unreliable sources, media using other media as sources, an active insurgent propaganda machine, and the pack journalism at its worse," Capt. Jeffrey Pool, a spokesman for the 2nd Marine Division, said in an e-mail to news organizations.

Witnesses in Ramadi said they saw some of the armed fighters instruct a journalist for an Arabic-language news outlet to report that Zarqawi's group, al Qaeda in Iraq, had taken over the entire city. The Arabic outlet by late Thursday was reporting only that the fighters had held some streets of the city center -- a description of events in line with the eyewitness accounts and reports from other news organizations. News directors for the organization did not respond to requests for comment. The news organization is not being identified for security reasons.

In Baghdad, Maj. Gen. Rick Lynch, the top U.S. military spokesman in Iraq, denied at a news conference what he called the "spurious reports" coming out of Ramadi.

"The idea that there's this mass uprising and the insurgents took control of the city is incorrect," Lynch said. "When I hear reports about how the insurgents have taken over the town and I call the commander on the ground and he says I have no idea what you're talking about . . . ."

Numerous provincial officials, residents and witnesses in Ramadi separately reported the appearance of the armed men, however. Witnesses said they saw dozens of the fighters in the streets of the city center after about 7 a.m., and saw at least one impromptu checkpoint in which roughly 10 fighters were checking the identities of each driver.

Fighters at one roadblock abducted and later killed a city official, Mohammed Khalef, a transportation official for Ramadi, said Khalid Qaraghouli, a spokesman for the Anbar provincial government.

Mohammed Hamed, an Anbar government official, said the show of strength included "more than 200 armed men, including Arab fighters."

"There were no American Marines or government troops or policemen," Hamed said. "The insurgents were in a show of strength reminiscent of the power displays of the Saddam regime."

Hamed identified himself as a deputy governor of Anbar province. Marines said he was a tourism official in the provincial government.

Insurgents left the streets by late morning, as Marines entered in significant numbers, the witnesses said.

The U.S. military, in a sharply divergent report, said the only incident of the day was an attack by rocket-propelled grenade on a U.S.-Iraqi military observation post. There were no injuries or damage, the military said.

Marines did not immediately respond to an e-mail inquiry as to whether Marines had been present in the city center at the time of the alleged appearance of armed fighters.

Pool, the 2nd Marine Division spokesman, said its second-ranking officer and a half-dozen other officers entered Ramadi on Thursday for a meeting with tribal leaders, without incident.

Anbar province, a vast region whose population is concentrated along the Euphrates, has become a base and funnel for attackers targeting the U.S. military and the U.S.-supported Iraqi government. Since late April, Marines have led repeated offensives to try to drive out insurgents and disrupt their supply lines. The latest offensive, Operation Iron Hammer, involving 2,000 U.S. and Iraqi forces, continued Thursday across the Euphrates from the town of Hit, the Marines said.

The Marines have credited the offensives with helping persuade tribal and religious leaders in the province to join in what Marine commanders described as a breakthrough meeting Monday in Ramadi. Thursday's meeting was a follow-up session, meant by the Sunni leaders to produce a plan acceptable to the United States for withdrawing Marines from Ramadi.

The meeting played out despite the unrest reported in the town. Adnan Khamis Mihana, contacted by telephone, said he and eight other tribal leaders, clerics and former Iraqi army officers had agreed to propose creation of two brigades that would include Anbar Sunnis to secure Ramadi in the absence of U.S. troops, and agreed to ask for a timetable for U.S. withdrawal from the city.

A similar security proposal in Fallujah in early 2004 helped draw a heavy insurgent presence to that Anbar city, leading to the November 2004 assault by thousands of U.S. troops that left much of the city in rubble. The city has since been largely rebuilt.

The nine community leaders at the meeting in Ramadi pledged to kill any armed man who appeared on the streets of Ramadi after a withdrawal, Mihana said. Tribes of those men would be barred from seeking blood money or revenge, he said.

Mihana said community leaders also asked the American forces to stay away from polling sites during the Dec. 15 national elections. Brief clashes with U.S. troops present for a constitutional referendum Oct. 15 helped keep most voters at home in Ramadi, leading to only a 2 percent turnout in the city.

Asked how he expected the Zarqawi group to respond, Mihana said: "We will send them this agreement, and we will ask them to stick to what we agreed. But I don't think they will abide by it."

Residents of Ramadi, a city gutted and blighted by months of fighting between insurgents and U.S. forces, spoke bleakly.

"If today's meeting fails, then Ramadi will follow in the footsteps of Fallujah, Tall Afar and Qaim, because options for the Marines have run out," said Jamal Ali Dulaimy, a 48-year-old trader. "This is the last way out."

"I don't think today's meeting will lead to any good results," said Haifa Omar, a 30-year-old primary school teacher. "The Ramadi residents meeting here have no authority, nor any control over the situation in the city, because the real authority is in the hands of al Qaeda, who are running the city as they wish," she said. "They are looking for fighting and death like we are looking for our daily livelihood."

Separately on Thursday, a mortar landed just inside the sprawling Baghdad compound of Iraqi President Jamal Talabani, hitting what officials said was an unoccupied civilian house. There were no injuries.

Also in Baghdad, Lynch said the number of suicide bombings in November was the lowest in seven months -- 23. The U.S. military recorded 1,330 roadside bombings in November and 68 car bombings, Lynch said. He gave no casualty totals.

Correspondent Jonathan Finer and special correspondents Naseer Nouri and K.I. Ibrahim contributed to this report.