Hundreds of suspected criminals were detained in an Iraqi police sweep in a Baghdad neighborhood while Filipino officials continued Tuesday to work toward the release of a hostage taken by Iraqi militants.

The Baghdad (search) operation Monday involved dozens of Iraqi police officers and was intended to crack down on "criminals, kidnappers and looters," Hussein Ali Kamal, the deputy interior minister, said Tuesday.

Authorities arrested 527 suspects, said Sabah Qassem, an Interior Ministry information officer.

Just after dark, police in pickup trucks and sport utility vehicles spread through the Bab Alsheikh neighborhood and snatched suspects off the streets. Some fought back, setting off dozens of small gunbattles. One suspect died and two were injured while resisting arrest, Kamal said.

Associated Press Television News video showed dozens of detained men sitting on the ground. It was not immediately clear where the men were taken.

In the oil-rich city of Kirkuk, Kurdish security forces captured 15 militants, including a man believed to be a senior leader in a local group linked to Al Qaeda (search), an official in a pro-American Kurdish party said Tuesday.

Among those arrested late Monday was Hemen Banishiri, reportedly the second-in-command for the radical Kurdish group, Ansar al-Islam (search), said Saadi Ahmed, a senior member of the Patriotic Union of Kurdistan's political wing.

Hostage's Fate Unknown

The Philippines (search) said Tuesday it would withdraw its tiny peacekeeping force from Iraq as soon as it can — but that doesn't mean it will be earlier than planned — in response to threats to kill a Filipino native.

Officials are trying to obtain the release of a captive Filipino truck driver after terrorists in Iraq kidnapped him and threatened to kill him unless his native country withdraws its 51-person force home.

The Filipino government issued a statement Tuesday but was unclear as to whether it was advancing the pullout as demanded by the Iraqi militant kidnappers, or was sticking by its commitment to withdraw its peacekeepers on Aug. 20 as planned.

The confusion may have been deliberate as President Gloria Macapagal Arroyo (search) seeks to maintain her staunch support of the U.S.-led war on terrorism while avoiding a possible domestic backlash if Angelo dela Cruz (search), a 46-year-old father of eight, is beheaded.

"The Philippine government, consistent with its commitment, will withdraw its Philippine humanitarian contingent forces in Iraq as soon as preparations for their return to the Philippines are completed," Foreign Affairs Undersecretary Rafael Seguis said in a statement.

However, when the Arab television station Al-Jazeera aired the statement, Seguis was quoted as saying the withdrawal would be made "as soon as possible."

The Philippine government, which has imposed a news blackout on the crisis, did nothing to clarify the issue.

"Let us leave the government to do what is necessary to save the life of an innocent Filipino and to uphold our nation's interest," presidential spokesman Ignacio Bunye said.

"It is not for us to judge and raise our voices now that Angelo's life hangs in the balance. This is the most sensitive point in the hostage crisis. We must unite behind Angelo's family, keep our peace and pray hard."

The militant group, Iraqi Islamic Army-Khaled bin Al-Waleed Corps, issued a statement at midnight Monday Philippine time (11 a.m. EDT) that suddenly advanced a deadline for Philippine action on the group's demands and gave Manila only three hours to respond.

The deadline — the third since dela Cruz was snatched last Wednesday — passed with no indication on his fate. His kidnappers said he had been moved to the place where he would be killed, and Al-Jazeera aired a plea from the captive, asking Arroyo to yield to their demands.

Around 9 a.m. EDT, the Phillipine embassy in Baghdad told Fox News Channel that as of now, there was nothing new to report about dela Cruz and that they didn't expect anything new "at this moment." An embassy official said to try calling back in two hours. Officials would not confirm nor deny an earlier report that dela Cruz may be released on Tuesday.

Dela Cruz wore an orange garment similar to those worn by two other hostages who have been beheaded — American Nicholas Berg (search) and South Korean Kim Sun-il (search). He asked that his body be sent to the Philippines for burial should he be killed.

"We don't know anything," said Feliciano dela Cruz Jr., brother of the captive. "We are asking our president where our brother is."

Military spokesman Lt. Col. Daniel Lucero said a plan was in place for a "phased pullout" from the three areas in central Iraq where the Filipinos are based.

"The troops have been pre-warned that they may be asked at any time to move out," he said. "That means they should pack up. But we have not gotten the final order to go."

Recognizing the fine line that Manila was taking to obtain dela Cruz's release while remaining one of Washington's closest supporters, Secretary of State Colin Powell called Arroyo.

"We applaud President Arroyo's decision not to give in to terrorists and not to agree to an early withdrawal of Filipino forces," State Department spokesman Richard Boucher said Monday.

Continued Violence in Iraq

Meanwhile, several explosions were heard Tuesday in Baghdad.

At least one of the blasts appeared to have been triggered by a hand grenade tossed at a U.S. patrol in central Baghdad, said Master Sgt. David Larsen of the 1st Cavalry Division. No U.S. casualties were reported.

Also in Baghdad, an American helicopter circled over a burning U.S. Humvee on the road leading to the city's airport. The military had no information on the incident and it was not immediately clear if anyone was hurt.

In the northern city of Mosul — part of the so-called Sunni Triangle (search) — guerrillas hiding in an alley opened fire on a passing Iraqi National Guard patrol, killing one and wounding nine, authorities said. The guard forces counterattacked, killing one insurgent and wounding another, an Iraqi officer said on condition of anonymity.

Iraqi officials have been talking increasingly tough about those who continue to carry out attacks across the country — even though the 2-week-old Iraqi government has discussed offering a limited amnesty to militants to put down the insurgency.

"Terrorism isn't just killing and blowing up bombs, whoever threatens the ordinary life of the people is a terrorist," President Ghazi al-Yawer told a news conference. "We have a very sharp sword ready for anyone who threatens the security of this country."

Al-Yawer's words appeared carefully chosen, reflecting a classical Arab symbol of might in the sword and threatening militants, some of whom have beheaded hostages, with their own chosen weapon.

Al-Yawer said the government planned to announce the amnesty soon, and he appealed to militants to seize the opportunity to lay down their weapons, or "there will be the sword."

The Associated Press contributed to this report.