(CNN) -- Eleven people were killed in Afghanistan Wednesday when an anti-Pakistan demonstration turned violent, a spokesman for the provincial governor of Kandahar said.
Hundreds of residents of Maiwand District in Kandahar province staged the rally, spokesman Javid Faisal said.
Most of the protesters were chanting against Pakistan, he said.
The demonstration turned violent when an armed group began protesting against the Afghan government and foreign and Afghan forces, Faisal said.
Gunfire broke out between police and the armed group, leaving eight of its members dead as well as three civilian motorists.
Ten people were injured and 30 suspects were arrested, Faisal said. Police also seized a vest made for a suicide bomber and a motorcycle primed with explosives, he said.
Initial investigations show the armed group came from the Pakistani side of the border, he said.
The clash comes against a backdrop of renewed tensions on the border of Pakistan and Afghanistan.
Afghan and Pakistani troops have clashed in recent weeks, prompting anti-Pakistan protests by some Afghan residents.