While protests continue on the streets of central Kiev, the cities in the west of Ukraine are slipping towards autonomy with new parallel governments and security forces that have openly admitted they have deserted to the side of protesters.

In Lviv, the heartland of Ukrainian nationalism, firearms have been stolen from local military bases and police are no longer to be seen on the streets.

Amid talk of civil war, few want to see any permanent division between the country's mainly Russian-speaking east and the more pro-European west, but many admit there is a risk it could happen.

"The parliament of Ukraine has to change the law and pass responsibilities for security into the hands of local elected authorities," said Lviv's mayor Andriy Sadovyi, who has emerged as one of the leading power brokers amid a brittle coalition of municipal and regional assemblies.

"Those countries that have a high level of self-government and self-organisation are the most successful," he said.

Lviv has been providing money, personnel and materials for the rolling anti-government protests in Kiev since they broke out in November. Many have done a stint on the barricades.

Thirteen people from Lviv have been killed since violence broke out this week, but injured people have been trickling back for weeks. "One of my friends came back without a hand. He was 23," said Sofiya, who runs a hostel in the centre of Lviv with her husband.

Ukraine is divided into the nationalist west and pro-Russian east.

A similar breakdown in law and order followed by the seizure of control by local authorities has occurred across western Ukraine, including in the cities of Ivano-Frankivsk, Ternopil, Khmelnytskyi and Lutsk. Sadovyi said he was in close contact with his counterparts in all those places.

Lviv's affinity for Europe has long roots. Before falling under Soviet rule after the second world war, the city was a trading hub in central Europe, first within the Polish empire and then the Austrian empire.

There is little doubt that people in Lviv would oppose any deal between protesters and the government that did not include the immediate removal of president Viktor Yanukovych, who has tightened Ukraine's links to Russia.

"If Yanukovych was a gentleman, he would hang himself," said Olena, a student watching coverage of Kiev's protests on a big screen in central Lviv. "We are waiting for the moment he goes or the moment when something happens to him."

When deadly clashes broke out this week in Kiev, Lviv's police stations, the prosecutor's office and the local branch of the security services were attacked with cobblestones and molotov cocktails. Cars were set on fire; the burned chassis of many are strewn across the city.

Many condemn those behind the violence as foreigners – provocateurs acting in the interest of shadowy security forces or radical youths. But others describe it as a spontaneous outburst. "It had to be done otherwise nobody would have listened to us, " said Solamiya Pavliv, a student in the city.

At one military base, two people died in a fire and the chief of police in Lviv, Sergei Zyubanenko, said 1,000 firearms including Kalashnikov assault rifles and Makarov pistols were taken, as well as large amounts of ammunition.

"If the confrontation continues in Kiev, I can't exclude that in Lviv there will be an escalation," said Zyubanenko, who urged those officers under his command who had – conveniently – taken sick leave to make up their minds which side they were on.

"The police will not carry out any criminal orders … this should not be thought of as a betrayal," he said, adding that 70 police officers from the Lviv region had even gone to Kiev to support protesters. Footage from the capital showed the officers, still in uniform, receiving a rapturous welcome.

The local troops, who are answerable to Ukraine's interior ministry, will also refuse to carry out certain commands, Colonel Oleg Sakhon told journalists.

Oksana Pogorzhelskaya, a pensioner coming out of church in central Lviv, said: "The police are on the side of the people now."

Lviv's police force is now entirely invisible on the streets, apparently nervous of the hostile reaction their uniforms might provoke. But they are co-ordinating behind the scenes with civil defence units that have sprung up.

Several thousand men turned up on Thursday evening to be assigned into patrols – on foot, on bicycles, in cars and on horseback. "People are very angry … if we don't do this, the city will burn," said Sergei Savchenko, an artist who had volunteered with his friends. "We have been to Kiev many times, but now it is more important to be in Lviv."