Tensions are running high between ethnic Serbs and the Albanian-led government in Kosovo, south-east Europe.
Protesters have blockaded roads and reportedly fired guns after being made to put Kosovan-issued number plates on their cars.
There are fears violence between ethnic Serbs and ethnic Albanians could flare up again, 23 years after the Kosovo war.
Where is Kosovo and who lives there?
Kosovo is a small, landlocked country in the Balkans, bordering Albania, North Macedonia, Montenegro and Serbia.
Many Serbs consider it the birthplace of their own nation.
But of the 1.8 million people living in Kosovo, 92% are Albanian and only 6% Serbian. The rest are Bosniaks, Gorans, Turks and Roma.
How did Kosovo gain independence?
After the break-up of the Yugoslavia, in the 1990s, Kosovo – a province of the former country – sought its own autonomy and independence.
Serbia responded with a brutal crackdown against ethnic Albanians seeking independence.
This ended in 1999, with a Nato bombing campaign against Serbia, between March and June.
Serbian forces withdrew from Kosovo – but for many Kosovo Albanians and Serbs, the conflict has never been resolved.
The Nato-led Kosovo Force (KFor) is still based in Kosovo, with a current strength of 3,770.
In 2008, Kosovo unilaterally declared independence.
A total of 99 out of 193 United Nations countries now recognise Kosovo’s independence, including the US, the UK and 22 out of 27 EU countries.
But Russia and China, which do not, have blocked Kosovo’s membership of the UN.
And Serbian President Aleksandar Vucic has vowed Serbia would never recognise Kosovo as an independent country.
Neither Kosovo nor Serbia are in the EU – but:
Serbia has been an EU candidate country since 2012
Kosovo indicated it would like to apply by the end of 2022
Why has trouble flared up now?
Relationships between the Albanian-dominated government and the Serb minority have been strained for years.
Last weekend, tensions boiled over into civil disobedience.
Kosovo’s government wanted to make those in majority ethnic Serb areas swap their Serbian-issued car number plates for Kosovan-issued ones.
Some 50,000 people in these areas will not use Kosovan number plates because they refuse to recognise Kosovo’s independence.
On Sunday, ethnic Serbs in the northern region of Kosovo, which borders Serbia, barricaded roads and some men reportedly fired shots in protest.
Kosovo’s government postponed implementing the new rules, for a month.
Is Russia involved?
Kosovo’s government says Serbia is stirring up ethnic tensions and Russia is supporting it.
Serbia and Russia are traditional allies.
Following Russia’s invasion of Ukraine, Serbia refused to join other European nations’ sanctions regime.
Instead, in May, Mr Vucic signed what he said was a favourable gas deal with Russian President Vladimir Putin.
Russian Foreign Ministry spokeswoman Maria Zakharova blamed the Kosovo tension on Kosovan authorities imposing “groundless discriminatory rules”.
An MP from Mr Vucic’s party said Serbia would soon be compelled to begin the “denazification of the Balkans” – using the same language President Putin used to justify his invasion of Ukraine. He later apologised for his words.
Kosovo’s President, Vjosa Osmani, said Mr Putin could use Kosovo to widen the current conflict in Ukraine and destabilise Europe further.