More than 150,000 protesters rallied in Belgrade against Kosovo independence, as violence flared on the tense Serbia-Kosovo border and more countries recognized the breakaway state.
Chanting "Kosovo is the heart of Serbia" in front of the old copper-domed Yugoslav parliament, the crowds had poured into the capital in convoys of trains, buses and cars from all over the Balkan country.
"We must show that we are all against this fake independence. Taking Kosovo away from Serbia is like taking away your leg, arm or even child," said Vesna Vujacic, a 54-year-old teacher.
The rally came as several hundred former Serbian army reservists stormed a crossing post on the border with Kosovo, and Italy joined other European powers in recognizing the independence of the breakaway Serbian province.
Thick black plumes of smoke billowed above the border post of Merdare in southern Serbia, after the group of about 400 reservists attacked around 100 police with stones and burning tyres in a 20-minute assault.
It was the latest in a series of violent incidents that followed Sunday's unilateral declaration of independence from Serbia by Kosovo's ethnic Albanian-dominated parliament, a move vehemently opposed by Belgrade.
Two other border crossing points at Banja and Jarinje were closed for 24 hours from Tuesday after at least 1,000 Serbs from Kosovo and Serbia ransacked and torched the two sites.