The footage of a Russian helicopter being destroyed by Syrian rebels with a US-made BGM-71 TOW anti-tank missile has recently been shown by numerous media outlets across the globe.

In early-October, BBC journalist Frank Gardner reported citing an unnamed Saudi source that the kingdom had delivered another batch of 500 TOW anti-tank missiles to Free Syrian Army rebels. The news made headlines in media across the world. Then, the question arose: how many anti-tank missiles do Syrian rebels have and how they get them?

Some days later, the US delivered 50 tons of weapons to the so-called moderate Syrian opposition, saying there were only light firearms and ammunition. But not everyone believed that.

According to The Washington Post, the BGM-71 TOW missiles were delivered to Syrian rebels under a two-year-old covert program coordinated between the US and its allies in the region. After Russia launched its military operation against terrorists in Syria, the supplies were increased. Rebels call the missile the "Assad Tamer". Recently, they have been used successfully to slow the offensive of the Syrian Army and its allies.

The New York Times cited a rebel commander: "We get what we ask for in a very short time." In early-October, at least 34 videos were published online showing the use of the missile against Syrian troops. Dozens of tanks were destroyed. The article underscored that the US-made TOW anti-tank missiles began arriving in the region in 2013, through a covert program run by the US, Saudi Arabia and other allies. According to the newspaper, the program was even more costly than the $500 million Pentagon program to train Syrian moderate rebels.

In turn, an article in The Telegraph read that since Russia launched its military campaign in Syria the use of anti-tank missiles has increased by 800 percent.

Besides the direct drop of weapons from aircraft, missiles have been delivered via Jordan as well as Turkey and coordinated by the CIA. Investigative journalists have shed some light on the situation. For instance, The New York Times reported that transport aircraft of the Jordanian Air Force are involved in the delivery of weapons from Croatia to the Free Syrian Army across the Jordanian border.

The third way is delivery of the anti-tanks missiles directly from the US to Iraqi forces. Washington delivers to Iraq the domestic-made BGM-71 and Swedish AT-4. In the summer, the US delivered some 2,000 AT-4 missiles to Iraq.

It is hard to say how many of them (plus the Russian-made Kornet missile the Iraq army has used since September 2014) end up as trophies in the hands of Islamists and are used in Syria.

Recently, Russian media reported, citing "a source familiar with the matter," that hundreds of TOW missiles were handed over to Islamists.

The New York Times reported that in 2013 Saudi Arabia alone purchased 13,000 TOW missiles. According to other data, Riyadh bought 15,000 missiles, and previously the deliveries came from the US to Turkey.

In addition, Qatar has been delivering to Syrian rebels the Chinese-made HJ-8 missiles as well as the European-made MILAN systems.

As a result, it would be very dangerous to underestimate the number of anti-tank missiles which militants in Syria could have.