With a pair of thunderous nighttime explosions, Israel destroyed the hulking Palestinian municipal and security headquarters in this West Bank city Saturday, but mystery surrounded the fate of 15 armed Palestinians that Israel said were holed up inside.

The two controlled explosions ended the four-day siege and left mounds of smoldering rubble where the four-story building had stood on a hilltop overlooking Hebron.

Israeli soldiers moved through the debris Saturday looking for bodies, but as of Saturday afternoon, had found only weapons and ammunition, military sources said. About a dozen soldiers walked through the rubble and guarded the site, while a pair of bulldozers tore down the few remaining walls that survived the explosions.

More than 100 Palestinians, many of them police officers, came out of the building Tuesday and Wednesday, the first two days of the siege. The army said it arrested about 20 wanted men and let the rest go.

No Palestinians emerged after Wednesday, but Israel insisted that about 15 wanted Palestinians militants were still inside until the end.

A top Palestinian security chief said he believed all the Palestinians had left the compound before it was blown up.

"As far as we know, no one was inside" at the time of the explosions, said Jibril Rajoub, the head of Preventive Security in the West Bank. "We believed from the first moment that the aim was to destroy the building because it is a symbol for the Palestinian Authority."

According to the army, Palestinians inside fired on army positions early Friday morning, but then the shooting stopped. A Palestinian Cabinet minister was allowed to go into the building later Friday to try to negotiate a surrender.

The minister, Talal Sidr, said he couldn't find anyone inside, but that he was unable to search all of the large, heavily damaged building. The army said afterward it was certain that the armed men were still inside.

"There's nothing called the headquarters anymore," Mohammed Maswadeh, a Palestinian who lives near the compound, said Saturday. His windows, like many others within yards of the blast site, were blown out.

The first blast, set off late Friday night, sent sparks into the sky and brought down about a quarter of the building, Palestinian witnesses said. The army said it rigged the part of the headquarters where it believed the wanted men were still hiding.

Apache attack helicopters circled overhead after the first explosion. Smoke and fire could be seen from a ground-floor corner of the building, with flames shooting up the side of the building before dying down.

The army "detonated in a controlled manner a part of the building where wanted Palestinians were taking refuge and refused to turn themselves in," the military said in a statement, released before the second blast.

The second explosion, at around 3 a.m. Saturday, was even more powerful and brought down virtually all that was left of the building.

Army troops surrounded the Hebron compound early Tuesday as part of a West Bank military offensive that has confined some 700,000 Palestinians to their homes while soldiers search the West Bank for Palestinians suspected of links to deadly attacks on Israelis.

The open-ended campaign, prompted by a pair of suicide bombings that killed 26 Israelis, began a week and a half ago. Israel has raided seven of the eight major Palestinian cities in the West Bank.

The Hebron compound, used in the past as a base for British, Jordanian and Israeli forces, had housed offices of the Palestinian Authority's local governor and security forces.

Even before the explosions, the building had been badly damaged by missile and heavy machine-gun fire as well as military bulldozers as the army tried to force out those inside.

Maswadeh, the Palestinian living near the compound, compared the second blast to an earthquake, saying everything in his house shook: "I'd never seen an explosion like that. The cars nearby blew into the air and dropped down."

Ibrahim Shehadeh, another resident in the area, used to have a view of the headquarters. "Now, I can see everything from my house — the whole of Hebron," he said.

While operating in the Hebron area, soldiers have found an explosives lab containing belts ready for use in suicide bombing missions, the army said. More than 50 suspects from Palestinian security forces had been arrested throughout Hebron, the army added.

While the curfew remained in Hebron, it was lifted for at least five hours in the six other West Bank cities where the army is present in order to allow high school students to take their final exams.

Meanwhile, a Palestinian woman was shot dead and her husband wounded early Saturday in the Palestinian town of Deir al-Balah in the southern Gaza Strip, the Palestinian Ministry of Health said. The Palestinians said the couple was hit by machine gun fire from Israeli tanks. The army said it heard an explosion in Deir al-Balah, but did not return fire.