Baghdad ( CNN ) -- At least 16 people were killed and dozens were injured in attacks across Iraq Monday amid an apparent uptick in sectarian tensions . Most of the attacks targeted Shiites , including bomb blasts that injured pilgrims traveling to shrines just days before a religious celebration . Four Shia pilgrims were killed and six were injured when a car bomb exploded in Baghdad 's Karrada district , Iraq 's Interior Ministry said . Read more : One year later , Iraq war 's legacy remains unclear . And four Shia pilgrims were injured when three car bombs exploded simultaneously in the town of Balad Rouz , said Muthana Altimimi , head of the security and defense committee in Diyala province . Thursday will mark 40 days after Ashura , which commemorates the death of the Prophet Mohammed 's grandson . Shiite pilgrims often mark the occasion by traveling to shrines . Violence also erupted outside Baghdad . Seven people were killed and four were injured after their houses were bombed in the city of Mussyab , about 80 kilometers ( 50 miles ) south of the Iraqi capital , the Interior Ministry said . It was unclear who was responsible for the blast or why the houses were targeted . Monday 's attacks come amid rising sectarian tensions , as tens of thousands of Sunni demonstrators nationwide protest what they say is second-class treatment by Iraq 's Shiite-led government . Sunnis largely boycotted Iraq 's 2005 elections , leading to the emergence of a Shiite-led government . The move left the once-ruling minority disaffected , which contributed to years of bloody insurgency and sectarian warfare . Read more : Clashes erupt at Iraqi protest as sectarian tensions flare . The arrest of a group of bodyguards for Iraq 's Sunni finance minister fueled a surge in protests last week in Ramadi , about 110 kilometers ( 70 miles ) west of Baghdad , and in several other Iraqi cities . At least five people were injured Sunday when bodyguards for a top Iraqi official opened fire on stone-throwing Sunni demonstrators , the country 's Interior Ministry said . The clashes broke out after Deputy Prime Minister Saleh al-Mutlaq , who is Sunni , arrived to address crowds protesting in a plaza in Ramadi . In the wake of the protests , Prime Minister Nuri al-Maliki has defended his government . `` Nobody in Iraq has privilege over others , '' he said Friday , calling for increased dialogue . `` When we want to express an opinion , we have to do it in a civilized , humane and patriotic manner , '' he said . `` It is not expected to express your opinion by cutting off roads , steering strife and sectarianism , fighting , bragging about wars and dividing Iraq . '' CNN 's Yousuf Basil and Catherine E. Shoichet contributed to this report from Atlanta .
Attacks across Baghdad target Shia just days before a religious celebration . The victims include Shiites pilgrims traveling to shrines . Outside Iraq , dozens people are killed when houses are bombed .