March 20, 2011— -- Libyan leader Moammar Gadhafi's compound was hit by a missile strike late today, as a barrage of airstrikes by U.S. and European militaries destroyed Libyan defenses, rocked the capitol of Tripoli and buoyed the spirits of the opposition.
The strike, however, was not carried out by U.S. forces, an official said. Vice Admiral William Gortney said earlier today that the United States was "not targeting Gadhafi."
According to various reports, Gadhafi's compound was badly damaged, but it was not immediately known how many people were injured or killed.
A United Nations-backed no-fly zone enforced by the U.S. British and French aircraft is being enforced from Tripoli to Benghazi and the top third of the country. Spain, Belgium, Denmark, and Qatar have also joined the coalition.
"It's had a pretty significant effect very early on," Chairman of the Joint Chiefs of Staff Adm. Mike Mullen said today of Operation Odyssey Dawn on ABC News' "This Week."
"The no-fly zone has essentially started to have its effects. We are flying over Benghazi right now. He hasn't had any planes in the air the last two days," Mullen said of Libyan leader Moammar Gadhafi.
Gortney said today that the United States will will soon hand over command to a coalition partner, a point reiterated by several U.S. officials.
Gortney did not rule out that the United States will continue to fly patrols as part of the no-fly zone after this initial phase, but for now the United States will provide tanker refuelers, ISR and electronic jammers to the coalition no-fly zone.
"We judge these strikes to have been very effective in significantly degrading the regime's air defense capability," Gortney said of the 124 Tomahawks that have been dropped. "There has been no new air activity by the regime and we have detected no radar emissions from the air defense sites targeted and there has been a significant decrease in the air use of all Libyan air surveillance radars which is most of those limited to areas around Tripoli and Sirte."
American F-16s and AV-8 Harrier jets patrolled overhead, dropping bombs on pro-Gadhafi forces who were still continuing their offensive on rebel strongholds in eastern Libya, a Pentagon official said. About 10 miles south of Benghazi, 15 U.S. aircraft along with French and British fighters struck at Libyan mechanized forces advancing on Benghazi. Gortney said the strikes had killed dozens of Libyan troops.
Meanwhile, in Tripoli, anti-aircraft fire could be seen lighting up the night sky.
"Today there is hope, there is light at the end of the tunnel," opposition spokesman Jalal ElGallal told ABC News in Tobruk. "[With this intervention the fight is] evening up a little bit, so obviously the morale must be sky-high."
A spokesman for Gadhafi's government said all Libyan armed forces units have been told to follow a ceasefire. The ceasefire was being ordered after taking into account the civilian deaths, and the destruction of civilian and military buildings, the Libyan government spokesman told reporters. And all Libyans have been urged to participate in a peaceful march from Tripoli to Benghazi.
But U.S. officials are skeptical of the government's claims.
"We will watch his actions, not his words," a senior White House official said.
The opening salvo of the international operation, which military officials have described as a "multi-phase" operation to protect Libyan civilians, drew cheers from rebels across eastern Libya and a defiant warning from Gadhafi, who said he is prepared for a "long war."
"There is a big misunderstanding," Gadhafi's son, Saif, said on "This Week." "The whole country is united against the armed militia and the terrorists. Simply, the Americans and the other Western countries, you are supporting the terrorists and the armed militia. That's it."
The U.N. Security Council authorized an international coalition of 22 countries, including several Arab states, to use "all necessary measures" to protect Libyan civilians from attacks by Gadhafi and prevent a humanitarian crisis inside the country.
President Obama has stressed that military action in Libya will be "limited" to protecting the Libyan people, and administration officials say U.S. forces will only play an active, leading role in operations for "days, not weeks."
"We've seen the people of Libya take a courageous stand against a regime determined to brutalize its own citizens," Obama said in a speech in Rio De Janeiro, Brazil. "From the beginning, we have made clear that the change they seek must be driven by their own people."
But the international effort has also appeared aimed at directly hastening Gadhafi's fall from power, creating a window for Libyan opposition forces to go back on the offensive.
"We want the Libyan people to be able to express their will, I've said … and we consider that it means that Gadhafi has to go," French ambassador to the U.N. Gerard Araud said on "This Week."
It's unclear what would happen if they don't immediately succeed and Gadhafi clings to power.
"Before any further military commitments are made, the administration must do a better job of communicating to the American people and to Congress about our mission in Libya and how it will be achieved," House Speaker John Boehner said in a statement today.
Libyan Rebels Hail Intervention
Arab League support for international military action against Gadhafi, which had been a key factor in U.S. involvement in the effort, waned Sunday when the group's leader criticized the coalition airstrikes as breaking with the objective of the mission.
"What happened differs from the no-fly zone objectives," Amr Moussa told reporters after cruise missiles and B2 bombers pummeled Libya overnight. "What we want is civilians' protection not shelling more civilians."
U.S. military officials said the campaign, which included four American stealth bombers and several U.S. Harrier jets and Navy "growlers," carefully targeted Libyan air bases and aircraft, mobile air defense units and some ground forces loyal to Gadhafi.
The operation followed the launch Saturday of 122 cruise missiles from U.S. and British ships 500 miles off the Libyan coast at more than 20 targets around Tripoli, Misratah and Surt.
Libyan television reported that 48 people were killed, including civilians, and more than 150 wounded in the missile strikes, but there was no independent confirmation of the numbers.
Maj. Beverly Mock, a U.S. military spokeswoman aboard the USS Mount Whitney, which is the command and control center for the operation, said the strikes hit only targets that constituted a "direct threat to allied assets or civilians on the ground" and involved a "high degree of coordination between aircraft and personnel on the ground."
"[The strikes] they have been very effective," said Jalal ElGallal, a Libyan opposition spokesman in Tobruk. "Collateral damage is acceptable, as sad it is, because otherwise the casualties will rise to unacceptable proportions."
"Today there is hope, there is light at the end of the tunnel, there is a concentrated effort, the world community at long last stood up to impose the resolution they have passed," he said.
ABC News' Miguel Marquez, Huma Khan and Alex Marquardt contributed to this report.