World News : A glance at Russian arms sales to Syria

MOSCOW (World News) -- U.S. Secretary of State Hillary Rodham Clinton has accused Russia of sending attack helicopters to Syria, warning that the shipment "will escalate the conflict quite dramatically." Russian Foreign Minister Sergey Lavrov has rejected Clinton's claim, saying that Russia is only shipping air defense systems under previously signed contracts.

Russia has shielded Syrian President Bashar Assad's regime, its last ally in the Arab world, from international sanctions and has continued to provide it with weapons despite international outrage. It has shipped billions of dollars worth of missiles, combat jets, tanks, artillery and other military gear to Syria over more than four decades. Moscow says it's currently providing Assad with weapons intended to protect Syria from a foreign invasion and is not delivering the kinds of weapons needed to fight lightly armed insurgents in cities.

Here is a brief look at some of the weapons systems Russia has recently shipped to Syria or pledged to deliver in the future, according to official statements and Russian media reports. Russian government officials have remained secretive about arms trade, so a complete list of Russian weapons and other military gear sent to Syria is unavailable:

- Pantsyr-S1 air defense system. The truck-mounted short- and medium-range system combines air defense missiles and anti-aircraft artillery with sophisticated radar to hit aerial targets with deadly precision at ranges of up to 20 kilometers (more than 12 miles) and an altitude of 15 kilometers ( nearly 50,000 feet). It has further strengthened Syria's air defense system, which has been developed with Moscow's help since Cold War times.

Igor Sevastyanov, a deputy head of the Rosoboronexport state arms trader, said Wednesday that the Pantsyr contract is still being implemented. Sevastyanov didn't offer specifics, but Russian media reports have said that the contract envisaged the delivery of 36 such units, which include a truck mounted with guns and missiles together with a radar.

- Buk-M2 air defense system. The medium-range missile system is capable of hitting enemy aircraft and cruise missiles at ranges of up to 50 kilometers (31 miles) and an altitude of up to 25 kilometers (82,000 feet). It is a sophisticated weapon that is capable of inflicting heavy losses to enemy aircraft if Syria comes under attack.

- Bastion anti-ship missile system. Armed with supersonic Yakhont cruise missiles that have a range of up to 300 kilometers (162 nautical miles), it provides a strong deterrent against an attack from the sea. Russian Defense Minister Anatoly Serdyukov said last fall that Moscow would fully honor the Bastion contract. Russian media reports said that Russia already has fulfilled the Bastion deal, which was worth $ 300 million, and included the delivery of more than 70 Yakhont missiles.

- Yak-130 combat jets. Russian media reports said early this year that Syria had ordered a batch of 36 Yak-130 combat jets worth $ 550 million. Officials wouldn't confirm or deny the deal, which would significantly bolster the Syrian air force capability. The Yak-130 is a combat training jet that can also carry modern weapons for ground attack missions.

The Kremlin has insisted that the continuing Russian arms sales don't violate any international agreements and scoffed at Western demands to halt the trade. Underlining Moscow's defiance, a Russian ship carrying a load of weapons arrived In Syria just a few weeks ago amid international anger over Assad's refusal to honor a U.N.-sponso red peace plan.

The new Russian weapons supplies add to Syria's massive arsenal of hundreds of Soviet-built combat jets, attack helicopters and missiles and thousands of tanks, other armored vehicles and artillery systems. Russia said it also has military advisers in Syria training the Syrians to use the Russian weapons, and has helped repair and maintain Syrian weapons. Some experts alleged that the helicopters Clinton said were en route to Syria could be old ones that underwent maintenance in Russia.