The missiles that flashed through the gloaming Thursday to demolish the El Shifa Pharmaceutical plant here did so with remarkable precision. The factory's walls fell inward while, not 10 feet outside them, 55-gallon drums remained standing. The roof came down, the assembly line was blown apart, and the candy factory that shares a wall with the plant was left intact.

It's the aftermath that has been untidy.

In the smoldering wreckage of El Shifa, the rogue government of Sudan perceived a gleaming public relations opportunity. The militant Islamic regime, which had routinely declined visas to American journalists because the United States has declared it a terrorist state, has ushered in reporters by the score since Thursday to photograph, videotape and broadcast live from a factory that -- whatever else it was doing -- made urgently needed medicines for a desperately poor country.

The seemingly endless footage of dark brown ibuprofen bottles and veterinary stocks from the bombed-out factory forced the Clinton administration today to do what only Sunday it insisted it could not -- release details of evidence that it contends proves the factory's connection to chemical weapons. In Washington, a senior intelligence official told reporters that the United States had in recent months obtained by clandestine means a soil sample from the plant site that contained "fairly high amounts" of a chemical used to produce deadly VX nerve gas.

"It doesn't have commercial uses that we know of; it doesn't occur naturally in the environment," the official said, adding that its presence in the soil at the plant led U.S. intelligence officials to the "unambiguous conclusion" that the El Shifa plant had been used to make a chemical that can only be used in nerve gas production. "That's pretty compelling," the official said.

The U.S. briefings came 24 hours after White House national security adviser Samuel R. "Sandy" Berger insisted that revealing such "physical evidence" would endanger U.S. intelligence sources. And they were coupled with the administration's first public acknowledgment of one of Sudan's public relations points -- that the facility did manufacture common medicines. "That facility very well may have been producing pharmaceuticals," State Department spokesman James Foley said.

In all, the exchanges -- reminiscent of U.S. public debates with Iraq over whether a chemical-weapons plant or an infant-formula factory was bombed in Baghdad during the Persian Gulf War -- looked from Khartoum like a potential publicity windfall for a Sudanese regime Washington has spent most of the 1990s trying to isolate.

"It's in their favor, unfortunately, because there's no evidence; it was a pharmaceutical factory," said a Khartoum resident interviewed before the U.S. announcement. The 38-year-old man said he opposes the ruling National Islamic Front but declined to give his name for fear its secret police would arrest him.

Other government opponents, the man added, have rallied at least temporarily around a regime that cannot supply a steady supply of clean drinking water to its capital, provides electricity only six hours a day and requires children to wear army fatigues to school -- green and brown for boys, blue for girls.

"Some people, they understand what's going on," he said. "But in the name of Islam they will support the government."

Today, the 22-nation Arab League, whose members have had their share of difficulties with Sudan, called for an independent investigation of the El Shifa facility. In a unanimous declaration, approved in Cairo at an emergency session requested and chaired by the Sudanese delegation to the group, the league also condemned the U.S. missile strike as "an attack on Sudan's sovereignty." A similar request brought before the U.N. Security Council today generated no response, and diplomatic sources said it seems unlikely that the 15-nation council will get involved.

Here in Khartoum, at the second news conference the government has hosted in as many days, President Omar Hassan Bashir went so far as to say that the missile strike has united a country that has been torn by civil war most of the past 30 years. "In actual fact, such events will only strengthen us," Bashir declared.

Certainly no other country in sub-Saharan Africa has felt anything like the intense, disapproving glare the United States has focused on Sudan in the 1990s. The Clinton administration slapped a trade embargo on Sudan five years ago and listed the country alongside Libya, Iraq, Iran, Syria and North Korea as a sponsor of terrorism. Two of its diplomats were expelled from the United States after secret tape recordings implicated them in a plot to bomb bridges and tunnels in New York City. In 1995, the U.N. Security Council declared itself "deeply alarmed" at Sudan's role in an assassination attempt on Egyptian President Hosni Mubarak.

A shared disdain for the Sudanese regime underpins the official U.S. enthusiasm for the governments of neighboring Uganda, Eritrea and Ethiopia, which Congress has voted to provide with "nonlethal" military aid that makes its way to rebels fighting the Sudanese government in its southern and eastern regions.

"Why are the people around us mad at us?" asked Sid Ahmed Hussein, director of Sudan's opposition Democratic Unionist Party. "The responsibility is with the National Islamic Front that opened up the country to terrorists and destroyed our reputation."

Today, a group of Sudanese women gathered in central Khartoum under a caricature of former White House intern Monica S. Lewinsky and chanted their government's claim that Clinton launched the strike against the El Shifa plant -- and a simultaneous missile attack on purported terrorist training camps in Afghanistan -- to divert attention from his personal legal problems. U.S. officials have described the Afghan targets as terrorist facilities linked to Osama bin Laden, the Saudi-born millionaire Clinton has blamed for the Aug. 7 bombings of the U.S. embassies in Kenya and Tanzania.

Diplomats here agree with opposition claims that such public demonstrations, mounted here almost daily since the missile strikes, are government stagecraft. "I think the number of people who came on their own, by their own transport, could be counted," said one diplomat. The government does not "have a popular base," he said. "Their power is based on suppressing opinions and a lot of security and the army."

The stagecraft extends to the visiting foreign reporters, who have descended on Khartoum from U.S., British, French, German, Japanese and Arab media outlets, picking through the rubble from which CNN has been broadcasting since the weekend. Some of the resulting coverage has appeared sympathetic to the line Sudanese officials are putting out. At this morning's news conference here, journalists sat at tables heaped with samples of antibiotics and headache remedies from El Shafir, which the government's information minister called "a household name in Sudan."

In explaining the case for the U.S. strike on the plant, the American intelligence official asserted that the United States also has evidence that plant directors have had communications with Emad Ani, an official at Samarra Drug Industries in Iraq, the organization believed by U.S. intelligence to be responsible for Iraq's chemical weapons program.

But most attention was focused on the soil sample bearing what the official identified as o-ethylmethylphosphonothioic acid, or EMPTA. The official said EMPTA's only known function is as a precursor agent for the production of VX and that it is "difficult to make."

"It's one of the harder parts of making VX," the official said. "Once you make this stuff, the rest of it's easy." Correspondent Howard Schneider in Cairo and staff writers Vernon Loeb in Washington and John M. Goshko at the United Nations contributed to this report. CAPTION: Sudanese officials walk through ruins of Khartoum plant hit by U.S. missiles. ec CAPTION: Sudanese police stand guard outside the chemical plant in Khartoum that was devastated by U.S. missiles last week. ec