They stand at intervals of a few metres around the presidential building, heavily armed, wearing fatigues, helmets and body armour. Montenegro's government is sending a message to President Slobodan Milosevic - "if provoked we will stand and fight".
There are rumours of atakeover by troops of the federal government. Serbia's smaller, weaker partner in the Federal Republic of Yugoslavia has been moving towards break-away for years and it fears Mr Milosevic is about to use the cover of Nato strikes to reassert his failing power here.
It is reported that senior figures in the Yugoslav units based in Montenegro have been replaced by hardliners more loyal to Mr Milosevic.
The allies are taking the threat seriously. The Foreign Secretary, Robin Cook, warned Mr Milosevic yesterday against opening up a front against Montenegro.
The Yugoslav president "should not now try to create trouble in Montenegro. He is in enough trouble himself. He has neither the time nor the resources."
Dragisa Burzan, Montenegro's Deputy Prime Minster, said there was imminent danger of a confrontation between Montenegro and Serbia. "If they are looking for any kind of confrontation that is their decision, not ours. We are not those who will stir up anything. We will try to do everything to stop major disruption here."
Mr Milosevic had made moves on Montenegro even before the Nato strikes. He tried to take editorial control of the television station but was rebuffed by Montenegro's government, which made a show of putting armed units in place around the building. That time Mr Milosevic backed down.
It is accepted here that his hand has been strengthened by Nato's action. When Montenegro was first hit by Nato bombs, Western diplomats privately expressed surprise.
They were worried about the destabilising effect. Yesterday, in a televised briefing in London, Mr Cook all but apologised. "Installations integral to [Yugoslavia's] air defence system had to be attacked; we had no choice. We've taken every possible step to limit and restrain those attacks."
Every day in Podgorica there are demonstrations by those who support Mr Milosevic. They vilify Nato and its political leaders. As each night of bombing passes there is a subtle but definite shift back towards the President.
In the city's park, under a statue of one of Montenegro's historic figures, a woman said: "What Nato are doing makes you feel like you really don't want to sign the Kosovo peace agreement. I'm generally against Milosevic's policy - at least I was before all this happened. Now I don't know. It's not good."
Intellectuals in Montenegro believe damage has been done and is irreparable. Srdan Darmanovic, of the Centre for Democracy and Human Rights, called the Nato action here a political catastrophe. "War is always very dangerous for pro-democracy forces, and in Montenegro pro-democratic forces are in power," he said. "All pro-democracy powers in Montenegro are in danger from this war. War is a paradise for all political forces who want to go back and it is a paradise for Milosevic and his supporters."
The fall-out from fighting across the border in Kosovo is also destabilising Montenegro. Since Saturday more than 32,000 Kosovo Albanians have arrived, fleeing their homeland in fear of their lives.
They have joined 25,000Kosovars who took refuge earlier in the conflict and 21,000 people from the Croatian and Bosnian wars.
Fourteen per cent of the population is now made up of people displaced from their homes in other republics and countries.
The government says Montenegro, economically crippled by sanctions as part of Yugoslavia, cannot support the refugees much longer. On Tuesday night in Podgorica a church that serves as a temporary home to Kosovo Albanians was hit by gunfire.
It is presumed the attackers were Montenegrins of Serbian origin, who represent some 9 per cent of the population.
Mr Burzan says that Serbs in the republic and their sympathisers are angered by the presence of the Kosovo Albanians and by the burden they impose.
The Deputy Prime Minister fears a backlash. He looks pensive, and says: "This situation is potentially explosive."