A wave of violence in the Pakistani port of Karachi has killed at least 31 people since Monday and prompted the country's interior minister to say the government will take “every possible action to restore peace.”

Authorities say 11 people were shot dead in Karachi on Tuesday, while at least 20 were killed the day before. Karachi has a long history of ethnic, sectarian and political violence by armed gangs suspected of links to Pakistan's main political parties. Officials say the violence killed more than 200 people in the city last month.

Pakistani Interior Minister Rehman Malik said Tuesday the government has had enough of the killings and will take stern action to stop them. Pakistani authorities boosted deployments of security forces in Karachi last month, but the violence continued.

Elsewhere, a roadside bomb blast Tuesday struck a vehicle carrying Pakistani soldiers in a northwestern border region, killing two of them. Officials say the attack happened as the troops were patrolling near the town of Ladha in the South Waziristan tribal area, bordering Afghanistan. South Waziristan is a stronghold of Islamist and al-Qaida-linked fighters.