A 41-year-old man from Llansamlet has been arrested on suspicion of having a firearm to endanger life. A 16-year-old boy, also from Llansamlet, has been arrested on suspicion of affray. Nothing has been proven. Neither has been charged.
Road closures are in place from the Asda roundabout on Upper Fforest Way right through to the A4067 dual carriageway.
That's everything we know.
Why this mattersSo what does "critical incident" actually mean?
It's not a routine call. It's the label South Wales Police only use when a situation is serious enough to need a response across the whole force.
And here, that response is big. Armed officers. A police helicopter overhead. Roads sealed off across a busy stretch of the A48 this evening.
There's footage going round online too. It appears to show armed officers checking out an Audi with a smashed driver's side window and a loose rear number plate. Police haven't confirmed that footage themselves. And they've asked people not to share unverified rumours while this is ongoing.
Chief Superintendent Stephen Jones, from South Wales Police, says quote "A policing presence will be visible in the area whilst this investigation is ongoing".
So that's the force telling you: this isn't over yet.
He's also asked people to stay away. He says people should avoid the area so police can deal with the incident and return things to normal.
That's a senior officer saying the scene itself is still being worked right now.
So what don't we know? A lot, actually.
Police haven't said who the target was. They haven't said who fired, or why. And they haven't said whether that 16-year-old boy was involved in the shooting itself, or caught up in something separate nearby.
One outlet, Nation.Cymru, reports that one person had minor injuries, and that police said they weren't aware of any major injuries or deaths. No other outlet has confirmed that independently. South Wales Police's own statements have focused on the two arrests, not on anyone hurt.
And the disruption has spread well past the cordon. A firework display run by Morriston Town AFC got cancelled because of the police operation. That alone tells you how much of the area this has covered.
A criminal investigation is now under way. Both people arrested are still in custody. Police haven't given any timeline for when the roads reopen.
So until South Wales Police says more, nobody outside the investigation knows who was meant to get hit, or why.
