The UN Security Council has widened an international arms embargo to include all rebel and militia groups in the Democratic Republic of Congo.
Thousands of guns were handed in during a recent disarmament drive
It will punish violators with a travel ban and freezing of assets.
The ban follows a recent push to disarm militias in the volatile east and comes after a pledge from the main Hutu rebel group to disband and go home to Rwanda.
Ethnic warfare, fuelled by ready access to weapons, has cost the lives of tens of thousands of civilians in the east.
The five-year war drew in six countries before it was declared over in 2002.
The French-drafted Security Council resolution expands on a weapons ban first imposed in 2003 on armed groups in the eastern provinces of Ituri and North and South Kivu that refused to accept the peace deal.
Only soldiers and police which have integrated into a national army are exempt from the weapons ban, but they must notify a UN committee in advance, co-ordinate with UN peacekeepers and have weapons delivered to designated sites.
Neighbouring countries - Burundi, Rwanda and Uganda - are also ordered to keep a registry of all flights and to ensure that their airports are not used to deliver illegal weapons to DR Congo.
The UN mission has more than 15,000 peacekeepers in the country, but has struggled to keep a lid on violence in the east - especially in Ituri province where some 50,000 people are estimated to have died since 1999.
Earlier this year, nine UN peacekeepers from Bangladesh were killed in an ambush, prompting an attempt to disarm militia groups in Ituri, which left scores dead.