President Bashar al-Assad's war with his own Syrian people is moving perilously close to Lebanon. Indeed, over the past few days, Lebanese opposition leaders have been voicing their suspicions that the Baathist regime in Damascus – in an attempt to distract attention away from the Syrian popular uprising – is deliberately stirring sectarian tensions in a country which has only just commemorated the 36th anniversary of its own terrifying 15-year civil war, which cost 150,000 lives.

In the northern Lebanese city of Tripoli on Friday, rival pro- and anti-Assad demonstrations were held and the Lebanese Government flooded the streets with troops and internal security force members. Tripoli contains a sizeable community of Alawites, the Shia offshoot to which the Assad family belongs, most of them with close family ties to Syria.

Rather more disturbing was that the Shia Hezbollah in Lebanon – the only serious militia in the country and Israel's principal enemy here – accepted Syria's claim that the opposition Lebanese Future Movement MP Jamal Jarrah was involved in what the Assad regime calls the "armed insurgency" in the Syrian cities of Deraa, Latakia, Banias and Aleppo. Syrian television has shown interviews with two extremely frightened men it said had been caught with weapons and one of whom had, it said, confessed to bringing money and guns into Syria on the instructions of Jarrah. The MP and his party have indignantly denied the claim, but a Hezbollah official now says that Jarrah should be brought before Lebanese justice.

So, too, has the Syrian ambassador to Lebanon, Ali Abdul Karim Ali, who visited the Lebanese foreign ministry – obviously on orders from Damascus – to demand that Jarrah be brought to justice. The Future Movement, whose leader, Saad Hariri, remains the caretaker Lebanese Prime Minister in the continued absence of a government in the country, indignantly protested that Ali's move was Syrian interference in the internal affairs of Lebanon. Hezbollah has been busily praising – like its Iranian sponsors – the Egyptian revolution while condemning the demonstrations inside Syria.

So far, most Lebanese have been very careful to distance themselves from the Syrian imbroglio. The Druze leader, Walid Jumblatt, wrote in his weekly editorial in Al-Anba last week that because of his "attachment to Syria and its people and its stability", he believed that the authorities in Damascus should "undertake an internal restructuring of their security forces" as other Arab states have already done.

He has a point, of course. For it is now all too clear that the enormous hatred of the brutal mukhabarat secret police in Syria lies at the heart of the protests. On Friday, the security police opened live fire at protesters in 14 separate towns and cities across Syria – clearly a decision taken at the highest level of the regime.

Among those suppressing the protests were soldiers from the infamous Fourth Unit of the Syrian army, which answers directly not to the chief of staff but to President Assad's younger brother Maher, whose name appears on the banners of many of the protesters.

Human Rights Watch, which talks from Beirut directly to eyewitnesses of the massacres all over Syria, now has the names of exactly 76 protesters killed – or murdered – by the security forces over Friday and Saturday. Based on online collaboration, Syrian human rights activists have 112 names. Clearly about 100, including young children, died in a 48-hour period, but some bodies were not taken to hospitals where the state security police were noting their names and insisting that their burials should be private.

It is an odd phenomenon of all the Middle East revolutions that security police gun down protesters – and then gun down mourners at the funerals, and then shoot dead mourners at the funerals of those mourners shot dead the previous day.

According to Human Rights Watch's senior researcher on Syria, Nadim Houry, the death toll since the demonstrations began now totals 300. "It's clear that the Syrian security forces are ready to go very far to quell this," he says. "As far as this goes – and the other revolutions – it's a blast from the past. These regimes don't learn from each other – the protesters do. It would be funny if it wasn't so tragic. The language of the regimes – of foreign plots – is falling apart; people don't buy it any more."

Ironically, President Obama was the only international leader to suggest a "foreign hand" in Syria's crisis. He said that Iran was supporting the "outrageous" behaviour of the Syrian authorities.

Many Arabs were appalled that Mr Obama would apparently try to make cheap propaganda over the tragedy – there is, in fact, not the slightest evidence that Iran has been actively involved with the events in Syria – when he might have been dignified enough to have sent his sympathy to the mourners and told the protesters that America was with them.

But as Nadim Houry says, many regimes in the region – the Saudis, the Iranians, the Israelis and Turkey, for example – will be happy if Bashar Assad survives. "The real problem is, where do you go from here?" he says. "The regime has drawn its 'line in the sand'. But it did learn from other Arab revolutions to keep crowds from the centre of cities.

"In Homs, protesters pitched tents in the central square but the security forces arrived en masse and broke them up, tore down the tents and washed the streets overnight. A man living next to the Homs square told me that 'When the sun rose, it was almost as if no one had been there the night before'.

"Then on Friday, when people began to walk into Damascus, they were simply shot down in the suburbs. Only in Banias on Friday did the Syrian mukhabarat leave the city – and the protests there passed off peacefully."