It isn’t the smokestacks from the immense factories around the outskirts of Mariupol.

True, they belch sulphurous plumes across the immensity of the steppe. But no, that’s not why smoke grits your eyes and snags your throat in the city centre today.

It’s because the police station is still on fire.

Two bodies lie in the street They pull back the blanket to reveal one of the dead men has a broken arm (see picture, below).

“See!” Men scream at us. “No guns. He was injured. He was not fighting.”

A few blocks away the barricade of tyres around a government building is on fire. More smoke.

In the road men and women are building a new barricade. They fear the Ukrainian soldiers will come again in their armoured personnel carriers and attack here, as they assaulted the police station earlier with fatal consequences.

A Land Cruiser screams up, pockmarked with bullet holes, one tyre punctured. Men throw more pallets on the barricade.

Sergei, once resident in Aberdeen, approaches: “Please, my friends, please tell the truth. We are not terrorists. We have no weapons.”

A plea against Kiev’s insistence that it is acting against pro-Moscow “terrorists”.

Even as he speaks to me, another man has accosted our producer to tell her that we are talking to “terrorists” who have taken over the city.

Claim and counterclaim. But whatever and whoever, it seems clear that Ukrainian forces unleashed their guns upon Mariupol today and appear to have achieved precious little beyond alienating further the sizeable element of the population which wants rid of them altogether.

For more from Mariupol, follow @alextomo on Twitter.