According to this XKCD what-if?, the explosion of a pressure cooker is not dangerous in itself, the heat is the sole danger.
They can explode, in a sense, but not as violently as you might fear (or hope). The pressure inside a consumer cooker doesn’t go above about two atmospheres—about the pressure inside a can of soda. Those levels can be dangerous, but they’re generally not high enough to cause the metal to violently rupture.
The blast couldn’t even fling the lid very far. If you mounted a rifle-style barrel on a pressure cooker, even in ideal circumstances it wouldn’t be able to fire the lid much faster than you could throw it.
But then, this fire department blog (in Spanish) warns of the risks of pressure cookers. This is an image after an accident:
And it seems there was a case of a pregnant woman killed by head injuries, but it doesn't detail the accident.
Is there any evidence or studies which could clarify this?