PASULJANSKE LIVADE, Serbia (Reuters) - Under the keen eye of President Aleksandar Vucic and foreign diplomats, Serbia’s military flexed its muscles on Thursday, firing live ordnance in a mock attack on insurgent positions at a training ground east of Belgrade.

The training drill, dubbed Synergy 2018, came three days after Kosovo police used force to scatter Serb protesters in the town of Kosovska Mitrovica in Kosovo’s restive North and briefly detained a Serbian government official.

The incident soured already tense ties between Serbia and Kosovo, its former southern province which declared independence in 2008 after a bloody war a decade earlier.

Army commander Gen. Ljubisa Dikovic said the exercise, involving more than 900 troops, was a part of training plans for 2018.

“We have always had good soldiers, we want to have more of them ... we want them to be even better trained,” Vucic told reporters at the Pasuljanske Livade training range.

Serbia’s military budget in 2018 stood at 70.5 billion dinars (595 million euros), 23.6 percent more than last year.

Its forces are largely using Soviet technology from the 1980s and Belgrade wants to modernize its kit. Some of the weapons used in the drill were obsolete but still functional.

“We pulled them from depots, refurbished ... and as you could see, they worked well,” Vucic said.

Serbia is a European Union candidate country but one of the few Balkan states not in the 29-member NATO alliance, which is hugely unpopular among Serbs since its 1999 bombing campaign to drive Serbian forces out of Kosovo. Alliance peacekeepers are still deployed there.

In 2006 Serbia, which has adopted military neutrality, joined NATO’s Partnership for Peace program and in 2015 signed the Individual Partnership Action Plan - the highest rung of cooperation between the alliance and a country not aspiring to join.

Serbia also fosters close military ties with Russia, its traditional Orthodox Christian and Slavic ally.