According to Yugoslav sources, 4. Yugoslav Army quickly advanced into Trieste because local antifascist forced German garrison to abandon defence of entire city and to retreat to few strong points. Local partisans could not alone liberate entire city, but they linked with regular Yugoslav forces and guided them into town. Without their help, Yugoslavs would be lost in large city, and surely NZ division could alone claim Trieste garrison.
In many cases German troops, surrounded and in desperate situation, usually refused surrender to Yugoslavs if they learn that Allies are near. That led to more bitter combat and high casualties for both sides.
Some of fortified positions (where most of combat took place) in Trieste itself were:
Elba factory- Yugoslav 3. and 4.Dalmatian brigade aided with Slovenian and Italian antifascist overrunned estimated 1200 ss troops, sailors, Četnik and Italian fascist. In factory were 3 AT and 6 AA guns. On the walls around factory were bunkers. After mortar and AT fire Yugoslav assault groups reached roof of the building and defenders surrendered.
Rocol(Monte Bello) barracks- 11.Dalmatian brigade surrounded the barracks and captured them after short exchange of fire(including panzer faust fire) Yugoslavs had 4 dead and 2 wounded, around 600 Germans were POW. Germans even improvised bunkers of food bags.
San Marco Shipyard- German navy infantry unit there refused surrender to 11.Dalmatian brigade because German commander obviously had contact with NZ tank unit and waited for their intervention. But Yugoslav commander, irritated by NZ capture of San Giusto fortress that was surrounded by his troops threatened to use his AT guns against any non Yugoslav tank in his zone of responsibility, and NZ troops retreated. Yugoslav casualties there were 14 KIA and 10 WIA. Around 400 Germans were captured (including 21 officer) and 54 lay dead.
Palatia Beltrano in Via Zanelli street and ex Jewish school in Via del Monti (ss and sailors) - were captured by combined force of Trieste partisans and Yugoslav regular troops after workers improvised fire throwers of fireman equipment and used them on both buildings.
Trieste garrison had 10 battalions and 37 batteries, in all 11.000 men (parts of 188 division, 509.Sich. battalion, 7. ss replacement battalion, navy, artillery and policy units +Italian fascist militia and navy, 600 NDH sailors, Slovenian Homeguard units).
Map of Trieste operation, from Rako/Družijanić book "11.dalmatinska brigada":