Washington (CNN) -- Nineteen U.S. warplanes, including Marine Corps Harrier jets, Air Force B-2 stealth bombers and F-15 and F-16 fighter jets, conducted strike operations against Libya Sunday morning, according to Lt. Cmdr. James Stockman of U.S. Africa Command.
It is the next phase in Operation Odyssey Dawn, which began about 3 p.m. ET Saturday with the launch of more than 110 Tomahawk Cruise missiles from U.S. and British warships and subs.
The U.S. Navy launched four Harrier "jump jets" from the USS Kearsarge, an amphibious assault ship now in the Mediterranean Sea. The Harriers "conducted strikes against Gadhafi's ground forces and air defenses, joining an international effort to halt an offensive against the Libyan populace," said Navy spokesman Cmdr. Danny Hernandez.
The U.S. Navy also flew EA-18 Growlers, which are special versions of the F/A 18 fighter designed to jam enemy electronic signals, such as targeting radar from enemy air defense batteries, Hernandez said.
The U.S. Air Force flew three B-2 stealth bombers, four F-15 and 8 F-16s in strike missions over Libya. Africa Command would not say what bases the Air Force planes came from, but some of the U.S. warplanes did require mid-air refueling by American air tankers during their mission, according to a U.S. Africa Command spokeswoman. All the warplanes dropped GPS-guided bombs during their missions, she said.
All American warplanes returned safely from their missions, according to U.S. Africa Command.
On Sunday, Maj. Gen. John Lorimer, spokesman for the British Ministry of Defence, said British maritime assets including a submarine and two warships are in theatre, backing the Tornado GR4s which returned to the Royal Air Force's Lyneham station Sunday morning.
'We're really setting the conditions for the implementation of the no-fly zone," said Lorimer.
"In order to do that we need to attack targets which are the integrated air defence system, which will include radars and command and control centers. We've got to deal with those first before being able to implement the no-fly zone as laid out by the UNSCR," he said.
Lorimer added that a multi-purpose Typhoon aircraft is ready to be deployed .
"Protecting the innocent and conducting combined operations are what we are designed to do," said Col. Mark J. Desens, commanding officer of 26th Marine Expeditionary Unit, the Marines operating off the Kearsarge.
"Our forces are doing both as part of the U.S. commitment to protect Libyan citizens."
Italy -- Libya's former colonial power -- announced that as of midnight Sunday, four Tornado warplanes and four F-16s will be made available.