(CNN) -- Violence rocked two major Iraqi cities Wednesday, including Baghdad, where a car bombing near a wedding party and two other bombings killed at least 20 people, police said.
In Mosul, a Sunni activist known to demonstrate against Iraq's Shiite-led government was assassinated, one of 10 people killed or found dead from acts of violence Wednesday in the northern Iraqi city, Mosul police officials said.
The slayings come amid an uptick of political and sectarian violence across Iraq, where more than 350 people died in acts of violence in May, according to a CNN tally.
And Wednesday's attacks come on what is becoming an especially deadly week in the country -- at least 110 people have been killed since Monday.
In Baghdad, two car bombs and a roadside bomb exploded in separate Sunni neighborhoods in Baghdad within 30 minutes of each other Wednesday evening, police in the Iraqi capital said.
One of the car bombs detonated near a wedding party in al-Diwan, a neighborhood in southwestern Baghdad, killing at least 16 people and wounding 42 others, according to police. It wasn't clear whether the wedding party involved Sunnis or Shiites.
The other car bomb exploded in a market in the al-Gazaliya neighborhood in western Baghdad, killing four people and wounding 17 others, police said. And in the al-Khadraa neighborhood in western Baghdad, a roadside bomb wounded six people, police said.
Meanwhile, Wednesday's killings in Mosul -- about 430 kilometers (265 miles) north of Baghdad -- were another sign of a shaky security situation in Nineveh, the province where Mosul is located and one of three Iraqi provinces that postponed April's provincial council elections until July because of violence.
Gunmen fatally shot Sunni activist Sheikh Hassan al-Jabouri with pistols equipped with silencers in central Mosul, a predominantly Sunni city, police said. No suspects have been announced.
Al-Jabouri was active in demonstrations demanding that the Shiite-led government stop what protesters call second-class treatment of Iraq's Sunni community. Since December, tens of thousands of such demonstrators have taken to the streets across Iraq.
Sunni Arabs had more political clout in Iraq during Saddam Hussein's rule, until his government was deposed in 2003 after the U.S.-led invasion. Under the Shiite-led government in the post-Saddam era, Sunnis have felt marginalized.
About two-thirds of Iraq's nearly 32 million people are Shiite and roughly a third are Sunni, according to the CIA World Factbook.
Also Wednesday, a suicide attacker detonated a car bomb at a police station in southern Mosul, killing two people and wounding seven others, police said.
And the bodies of three people who appeared to have been tortured and hanged were recovered from the Tigris River and sent to the Mosul morgue, police said.
The hanging victims appeared to have died Wednesday morning, police said. They have not been identified.
Also, Iraqi federal police killed four people in clashes with unspecified gunmen in eastern Mosul, police officials in the city said.
The clashes happened after people reported suspicious activity in a building. When police arrived, gunmen emerged and attacked them, the Mosul police officials said.
In other violence Wednesday, mortar rounds landed on offices of the Nineveh provincial council in central Mosul, wounding six people, according to police.
Wednesday's bloodshed comes amid an increase of violence across Iraq, much of it stemming from discord between Sunni and Shiite Muslims.
On Tuesday, at least 23 people were killed and more than 80 others were wounded in three explosions and three shooting incidents in Baghdad and Mosul, police officials said.
On Monday, at least 57 people were killed and 190 wounded in a wave of attacks in Baghdad and other cities, police said.