U.S. Secretary of State Hillary Clinton was in Libya Tuesday with a $10 million aid pledge, much of which is to fund efforts to track down missing weapons from the Gadhafi regime.

The country's National Transition Council, which replaced Libyan leader Moammar Gadhafi and which is internationally recognized as Libya's legitimate government, admits thousands of weapons -- including shoulder-fired surface-to-air missiles -- went missing during the chaos to unseat the previous regime.

"Unfortunately, some of these missiles could have fallen into the wrong hands," Gen. Mohammed Adia, the National Transition Council officer in charge of armaments, said recently.

The United States, its NATO allies and other countries in the region are concerned the missiles, which proved so effective in the hands of Afghanistan's mujahedin that fought Soviet occupation forces in the 1980s, will find their way to terrorist and rebel organizations.

Recent news reports indicate they indeed have.

Officials from Egypt's Ministry of the Interior say five groups of smugglers have been arrested while transporting Libyan weapons toward the border with Israel.

The Jewish state, as early as in July, had warned that Libyan weapons, including the shoulder-fired missiles, were being supplied to Hamas, the radical Palestinian group that controls the Gaza Strip and periodically attacks Israel with rocket fire.

The Washington Post reported that Egyptian officials said they are concerned the same types of weapons are available on the black market on the Egyptian side of the Sinai Peninsula, which borders the Gaza Strip and Israel proper.

"We are definitely concerned by reports of Libyan arms entering Gaza, especially anti-aircraft and anti-armor weapons," a senior Israeli official was quoted as saying, "We know that Hamas wants them and can pay for them."

The exact number of missing missiles is unknown. It was known that Gadhafi had about 20,000 Soviet/Russian-made missiles. Reports say 5,000-10,000 are unaccounted for.

Small and lightweight, they are ideal contraband for those with violence on their mind. The Strella-3, for example, weighs 35 pounds and is 4 1/2 feet long. It is easily capable of bringing down the fixed-wing and rotor aircraft Israel uses to patrol the Sinai and other areas, as well as civilian airliners.

The Sinai's Bedouin tribesman, who are thought to be heavily involved in smuggling goods and other items to the Gaza Strip, are believed involved in the weapons trade.

Cairo's ability to enforce the law in the Sinai is reportedly degraded since the collapse of the regime of Hosni Mubarak.

The U.S. military's Africa Command, to combat the smuggling of Libyan weapons to sub-Saharan Africa, has begun monitoring Libya's border area with aircraft.

"Since the beginning of the crisis, we have been actively engaged with our allies and partners to support Libya's efforts to secure all conventional weapons stockpiles, including recover, control, and disposal of shoulder-fired anti-aircraft missiles, Tommy Vietor, spokesman for the U.S. National Security Council told ABC News recently.

Reports indicate the U.S. State Department has a 14-member team in Libya to help the NTC secure weapons facilities as well as track down missing weapons. The United States is also reportedly allied nations to join in the effort.

While in Tripoli, Clinton met with top Libyan officials, including Mahmoud Jibril, who has taken over as Libya's prime minister, and interim leader Mustafa Abdul Jalil.

The visit, Clinton's first to Libya, included talks on good governance and U.S. willingness to support the NTC to restore calm in the country and rebuild after months of warfare, which continues in at least one major city, Sirte, Gadhafi's home town and key Mediterranean port.

British Foreign Secretary William Hague met with officials in Tripoli on Monday.