There are no easy answers in Syria's fog of war

Another mass killing in Syria, another day of claim and denial about who was responsible.

And another frustrating day as a journalist here, unable to prove conclusively that one side or the other took the lives of their fellow Syrians.

That many people died in Aleppo today is clear. How many is not. At least twelve, perhaps more than fifteen, fifty, say some on the ground.

Something exploded at the University of Aleppo. It happened at the university's Information Technology Academy. Some students were in the middle of exams.

Those who support the revolution say it was an attack by the regime. One says he saw a MiG jet overhead firing missiles: "I saw this with my own eyes. My eyes don't lie," he wrote.

The Government denies this. A spokesman in Damascus says two rockets were fired from a rebel-held area and exploded at the university. "It was a terrorist act."

Both explanations are plausible, but it is possible that neither are "true" - or at least tell the whole truth.

It defies logic that either side would deliberately attack a university. Mistakes are possible in war, but I'm not saying this was a mistake because I don't know.

I can't see what happened for myself because I'm a long way from Aleppo, in the capital Damascus. But even here it is hard to really know who is doing what to whom. Today I drove around the city for hours. I was, as usual, looking for trouble.

Passing a village near the airport, I heard a MiG warplane overhead and seconds later I saw a plume of white smoke. A target had been attacked. It was impossible to get to the area because it was blocked by military checkpoints that I could not get through.

In another suburb in the city there were bursts of machine gun fire near where I stood. People walked by as if nothing had happened. I saw neither the shooter nor the target. It was impossible to access the area because the army had sealed it off and I was not welcome there.

In a third suburb I drove past there were many single shots, as if a sniper was engaging a target. A rebel sniper? A Syrian soldier? I couldn't tell. It too is surrounded by troops and occupied by rebels. Neither side appears to want journalists there.

I try, believe me, but sometimes it's almost impossible to spend two minutes on the ground with a camera without being detained and questioned by the army or intelligence officials. All perfectly proper, no violence, but the message is clear. "Go. Now."

So we see snapshots. Scenes of a war that open and close almost simultaneously. Blink and you miss them. Try to prove what happened? That's tough. Prove who did it? Tougher still. Who bombed Aleppo? Sorry but I don't know - not yet. I'm trying to find out. I may know more soon, but not everything.