Washington (CNN) -- The U.S. government stepped up its humanitarian relief effort for Libya on Friday, sending two C-130 military transport planes loaded with supplies to neighboring Tunisia.
Each aircraft carried three pallets of aid supplies, including 2,000 blankets, 40 rolls of plastic sheeting and 9,600 10-liter water cans, according to a statement from the U.S. Agency for International Development.
The supplies, meant to help up to 2,000 people, will be handed off to Tunisia's Red Crescent organization for distribution, the statement noted.
The relief operation -- designed to help those who have fled the Libyan violence -- is named Odyssey Dawn, Pentagon spokesman Col. Dave Lapan said.
American authorities are considering multiple ways to assist in the crisis, but are currently focused primarily on humanitarian efforts, Secretary of State Hillary Clinton told reporters. The Obama administration remains deeply "concerned with the ongoing violence ... initiated and perpetrated" by the government of Libyan strongman Moammar Gadhafi, she said.
Clinton noted, however, that there is currently "a lot of confusion on the ground" in Libya that makes it tough to understand exactly what is happening there.
Addressing reporters on Air Force One, White House Press Secretary Jay Carney reiterated the administration's position that Gadhafi needs to step aside.
"Col. Gadhafi has no legitimacy and should step down and should cease all violence," Carney said. "We believe that that would result in a more peaceful Libya."
The violence in Libya escalated Friday as pro-government forces took control of Zawiya, a city near Tripoli, according to state TV. One source reported the deaths of 15 people and injuries to at least 200 others.
A doctor at a hospital in Zawiya told CNN "there is a river of blood" where the wounded were being treated. He described the situation as "very bad," with the facility running out of medical supplies.
Forces loyal to Gadhafi also clashed Friday with opponents of the regime in the eastern city of Ras Lanuf, opposition fighters and commanders said.
Roughly 200,000 people have fled the intensifying violence in Libya, according to the International Organization for Migration. The number of people trying to leave, however, has declined heavily as armed government forces have intensified their presence on the Tunisian border and on roads leading up to it, the United Nations refugee agency has noted.
A number of key congressional leaders have been pressuring the White House to establish a no-fly zone over parts of Libya to aid Gadhafi's opponents and ease the humanitarian crisis. Gadhafi's "air defense systems are certainly old and it (should not be) a major challenge ... to impose a no-fly zone," Sen. John McCain, R-Arizona, asserted Friday.
While the administration has shifted additional military resources closer to Libya, it has refused to commit to such a course of action so far.
CNN's Alan Silverleib and Barbara Starr contributed to this report