Iraqi townspeople enraged over civilian deaths were allegedly behind Tuesday's attack that killed six British military police (search) officers during a demonstration in southern Iraq, a local policeman said Wednesday.

A municipal official says British forces are giving civilian leaders 48 hours to hand over the gunmen responsible for the attack.

The U.S. military said Tuesday there had been 25 attacks on coalition forces over a 24-hour period, including a firefight in Ramadi (search), west of Baghdad, that killed four Iraqis and wounded two American soldiers and two Iraqis.

British military officials were meeting Wednesday with seven members of the city's administrative council in the nearby town of Amarah, seeking the killers' surrender, said Qassem Nimeh, an official in the mayor's office in Majar al-Kabir.

Nimeh did not say how they would respond if the attackers were not handed over before the 48-hour deadline.

"We hope that we'll be able to bring those who are guilty of these attacks to justice," Paul Bremer (search), the top U.S. official in Iraq, told reporters in Baghdad on Wednesday.

Bremer said Iranian Shiites (search) may be in Iraq trying to plan such revolts with Iraqi Shiites. He warned Iran to not interfere with the Iraqi reconstruction process.

In interviews with U.S. television networks Wednesday, Bremer said the coalition will not be deterred by "a few fanatics."

There were more coalition-led checkpoints installed around Iraq Wednesday after the latest attack in an attempt to safeguard U.S. and British troops.

Abbas Faddhel, an Iraqi police officer in Majar-Al-Kabir (search), said the British troops shot and killed four civilian demonstrators on Tuesday.

Armed civilians then killed two of the British soldiers in retaliation -- in front of the mayor's office -- and proceeded to chase four others to a police station, killing them after a two-hour gunbattle, Faddhel said.

Salam Mohammed, a member of a municipal security force, said one British soldier was shot and killed at the station's doorway and the other three were slain after Iraqi gunmen stormed the station and cornered them in a single room.

British Defense Secretary Geoff Hoon (search) said an "urgent review" was under way, and that reinforcements were ready if needed. "Depending on the results of that review ... we have significant forces available should it be necessary. Many thousands, certainly," Hoon said.

The incident had raised fears that attacks against coalition troops were spreading to previously calm areas like southern Iraq.

"I know that there was some tension in this particular town," Hoon told British Broadcasting Corp. television. "That arises out of the fact that it is routinely the case in a number of these southern towns for people to be armed and indeed for people to have quite heavy weapons, including machine guns."

After another fierce firefight Tuesday between Iraqis and British troops occupying southern Iraq, eight British soldiers were wounded, three of them seriously.

The day's violence began when British soldiers fired rubber bullets -- then live ammunition -- at demonstrators in Majar al-Kabir who railed against the presence of British forces in the city, said Abu Zahraa, a 30-year-old vendor.

He said the British had formally agreed a day earlier to let local police patrol the city.

Some accounts said British soldiers killed all four during the demonstration; another account said two unarmed protesters were killed during the demonstration and two other civilians were killed in the gunbattle at the police station.

On Wednesday, the station's walls were full of bullet holes. Broken glass and dried blood stains covered the floor.

A British military spokesman, Capt. Adam Marchant-Wincott, said it was possible there had been an agreement between British forces and local police allowing the locals to take over security for the city.

Marchant-Wincott couldn't say whether the British forces had fired at demonstrators but added that they would do so only if their lives were threatened.

Faddhel said there were about two dozen Iraqi policemen at the station who fled through a window during the gunbattle. Two were wounded. Faddhel said the Iraqi police asked the British military police to flee with them but the British insisted on staying.

In another attack, an oil pipeline was sabotaged Tuesday near Hadithah, 150 miles northwest of Baghdad, an Iraq oil ministry official said.

Television reports Wednesday showed oil flooding into palm groves and the Euphrates River. The official said saboteurs broke valves on the pipeline, causing the oil to spill.

It was the latest in a series of attacks against Iraq's power and oil infrastructure that has set back reconstruction efforts and increased blackouts in Baghdad.

The violence at the police station came in the mostly Shiite south, where resentment toward Saddam Hussein's government had been strong. There had been no substantial attacks there against U.S. or British forces since the end of the war and the area was considered relatively safe.

Defense Secretary Donald Rumsfeld called the pro-Saddam forces "dead-enders" and said coalition troops were making progress against them.

"Just as they were unable to stop the coalition advance in Baghdad, the death squads will not stop our commitment to create stability and security in postwar Iraq," Rumsfeld said Tuesday.

Elsewhere in the same town, a "large number" of Iraqi gunmen opened fire on a British patrol Tuesday with rocket-propelled grenades, heavy machine guns and rifles, Hoon said. The British returned fire, and one British soldier was wounded in the fight.

A rapid reaction force, including Scimitar light tanks and a Chinook CH-47 helicopter, came to help the ground troops but also came under fire, Hoon said. Seven people on board the helicopter were wounded, three of them seriously, the government said.

Hoon said commanders were investigating whether the earlier deaths and the later ambush were connected.

"These losses are a reminder that Iraq remains a dangerous place," Gen. Richard Myers, chairman of the Joint Chiefs of Staff, said at the Pentagon. "But we must continue to stand firm."

It was the deadliest day for coalition forces since May 19, when six U.S. Marines died, most in a helicopter crash and a vehicle accident.

Saddam loyalists, Sunnis and ex-army soldiers are suspected in the attacks. The Shiite-dominated south has been largely peaceful since the regime's fall. The Muslim sect had been long repressed by Saddam.

Forty-two British troops have died -- 19 in accidents -- since the war began March 20. Britain had suffered no confirmed combat deaths since April 6.

Fox News' Bob Sellers and The Associated Press contributed to this report.