Arab League observers had barely started work in Damascus when the message that their hosts most wanted them to hear was delivered with unmistakable force.

Two car bombs – the first since the start of the uprising against Bashar al-Assad's regime – caused carnage in the centre of the capital. And before the dust had even settled, the government had found itself a suspect. Al-Qaida did it, state TV reported, just as the terror group had caused all the mayhem throughout the country over the past nine months.

The two explosions reportedly targeted security headquarters in an affluent area of the capital. Syrian officials were almost as quick as the state mouthpiece to express their outrage, lamenting a loss of more than 30 lives and condemning those who would seek to do the country harm.

But any sorrow for the victims must surely be mitigated by the fact that the incidents fit straight into the official narrative: anti-regime activists weren't peaceful protesters wanting reform after all, and talk of peaceful change was always a veneer for the stalking horse of al-Qaida. Regime officials have made this their mantra since violence started to escalate in late summer.

The problem for Syria – and the key reason that 13 Arab League observers have finally made their way to Damascus to see things for themselves – is that the Sunni world did not believe them. Sunni states, such as Jordan, Turkey, Saudi Arabia and Qatar, had either downgraded or cut completely relations with the president, Bashar al-Assad, convinced that he has been consistently lying to them.

A violent jolt this morning may well give the men of the Arab League cause to reconsider.

Outside the capital, where the uprising is playing out, opposition groups and the militia that calls itself the Free Syria Army are deeply suspicious of Friday's events and just as wary of the Arab League delegation, which is being led by Sudan's former intelligence chief, General Mohammed al-Dabi – a man who was at the helm during the genocide in Darfur.

Turning a blind eye to human rights abuses has been a prerequisite for getting by in Omar al-Bashir's Sudan. And Dabi's 20 years in Bashir's service does not auger well for a rigorous probe into events in Syria.

The delegation has been promised access to any part of the Syria it wants. It would do well to make haste to the north, where the regular military is trying to finish off large numbers of defectors around Idlib, who have been hunted down during three days of fierce battles this week. Conservative estimates put the death toll among defectors at around 200. Around 100 still serving members of the military have also been killed.

Not one defector I have spoken to in the past six months has seen or heard of any member of al-Qaida or a jihadi organisation inside Syria since the revolt began.

To them, the regime's insistence of a foreign-backed insurgency manned by highly mobile jihad groups who consistently outmanoeuvre the Syrian army is pure self-serving fantasy.

There have, however, been signs in recent weeks that things might be about to change: Iraq's Anbar province is up in arms at the ongoing crackdown against Sunni towns and cities in Syria. And there have also been rumblings in Libya and southern Turkey. The persistent regime claims are starting to take on the feel of a self-fulfilling prophecy.

And after these blasts, the regime can boast that they were right all along. The enduring question is who will believe them.