Swiss voters on Sunday approved a measure to tighten the Alpine nation's gun laws, bringing the country in line with many of its European partners despite the objections of local gun owners, official results showed.

The Federal Chancellery said provisional results showed nearly 64 per cent of voters nationwide agreed to align with European Union firearms rules adopted two years ago after deadly attacks in France, Belgium, Germany and Britain.

The vote was part of Switzerland's regular referendums that give citizens a direct say in policymaking.

Switzerland has voted by 64 per cent to 36 per cent to align the country's gun laws with the EU, despite bitter opposition from activists who said the move was anti-Swiss

It had stoked passions in a country with long, proud traditions of gun ownership and sport and target shooting.

Switzerland, unlike many other European nations, allows veterans of its obligatory military service for men to take home their service weapons after tours of duty.

The Swiss proposal, among other things, requires regular training on the use of firearms, special waivers to own some semi-automatic weapons and serial number tracking system for key parts of some guns.

Gun owners would have to register any weapons not already registered within three years, and keep a registry of their gun collections.

Supporters of the measure, who included the Swiss parliament and executive branch, said similar measures adopted by the EU after deadly extremist attacks are needed to ensure strong police cooperation and economic ties with Switzerland's partners in Europe's Schengen visa-free travel zone.

They insisted it will not block law-abiding citizens from obtaining legal guns, but would simply do more to track them.

Switzerland is not an EU member, but it is in the Schengen zone.

Opponents insisted the proposal would violate Switzerland's constitution and do little to fight extremism or crime.

They said the weapons used in recent attacks in Europe weren't obtained legally, and argued the proposal would crack down mainly on lawful gun owners in Switzerland.

They were also angry at politicians for ramming through what they see as the latest diktat from Brussels.

Rejecting the proposal would have risked Switzerland dropping out of Europe's passport-free Schengen zone, as activists said the move was being forced upon them

Jean-Luc Addor, a populist Swiss People's Party lawmaker from the southwestern Valais region, said adopting the EU directive would be 'unjust, freedom-killing, useless, dangerous, and above all, anti-Swiss.'

'With no effect on the fight against terrorism, it will only hit honest, law-abiding citizens who possess legal weapons,' he wrote on his website.

'It's the epitome of injustice.'

Carmelo Lagana, project manager for foreign trade at economiesuisse, the country's top business federation, insisted Switzerland would suffer if Swiss police couldn't continue to have access to Schengen-zone databases.

He also said the country had an important say in negotiations with the European Union.

'It is Switzerland, as a member state, that has participated at every level the work to modify this European directive and it was exactly able to introduce some exceptions to preserve Swiss shooting traditions,' he said.

'You should know that the European Union wanted initially to totally forbid the acquisition of semi-automatic weapons, and in the end, we have a directive that doesn't ban it.'

Switzerland hasn't faced major extremist attacks like those that have hit France, Belgium, Britain and Germany in recent years, leaving scores dead.

Ahead of the vote, most of Switzerland's major political parties - except for the populist Swiss People's Party - favored the measure, with support strongest among Socialists and Greens.

The rift on the issue has fallen along a rural-urban divide, with city dwellers more inclined to back the EU directive.