Five people, including a child, were executed at a New Year's gathering in El Salvador early on Friday, while five gang members died in a highway shootout with police, an official said.
A group of men dressed in dark, military-style garb and armed with assault rifles broke into two homes during New Year's parties and killed five people, including a woman and a child, in the city of San Miguel, 85 miles (136 km) east of the capital, according to a police spokesman.
The massacre may be gang related, since the neighbourhood is controlled by the Mara Salvatrucha, the spokesman said. Security officials have said that gang members frequently dress in military or police uniforms when they carry out killings.
El Salvador's murder rate surged 70 percent in 2015 to one of the highest in the world due to increasing battles between rival gangs and security forces.
Another five alleged gang members were killed when they opened fire on police with revolvers and shotguns after being stopped in a taxi at a highway checkpoint in the southwestern municipality of Olocuilta, the spokesman said.