Israel has complained to Russia that Russian-made anti-tank missiles have reached Hezbollah guerrillas who used them against Israeli troops in south Lebanon, government officials said Friday.

An Israeli delegation traveled to Moscow earlier this week to deliver the complaint, said Asaf Shariv, a senior adviser to Prime Minister Ehud Olmert.

The anti-tank missiles proved to be one of Hezbollah's most effective weapons in combat with Israeli soldiers in Lebanon. Such missiles killed at least 50 of the 118 soldiers who died in the 34-day war that ended this week.

Another government official, speaking on condition of anonymity because he was not authorized to discuss the matter with the media, said the delegation was "senior," but refused to say who they would be meeting with in Russia.

Israel does not accuse Russia of directly arming Hezbollah, but complains that Russia sold the weapons to Iran and Syria, known supporters of Hezbollah, who then passed them on to the guerrilla group.

Russian Foreign Ministry spokesman Mikhail Kamynin said Russia maintains strict controls over its weapons sales, and that tight supervision "makes any inaccuracy in weapons destinations impossible."

Anatoly Tsyganok, head of Russia's Military Forecasting Center, ruled out the possibility that modern anti-tank weapons had reached Hezbollah through Russia or Syria.

"Any accusations alleging Russian or Syrian deliveries of anti-tank weapons to any forces in Lebanon are unfounded. The Israeli side has not presented any evidence of this, and it is unlikely that it will," Tsyganok was recently quoted as saying by the Interfax news agency.

"Most probably, such weapons, should Hezbollah militants really have any, might have been brought to Lebanon through third countries," he added.