Attacks including bombings of Shiite and Sunni mosques left 26 dead in Iraq, the latest in a surge of bloodshed that is raising fears of a return to widespread sectarian killings, officials said Wednesday.

Most attacks on Shiites are presumed to be carried out by the country’s branch of al-Qaida, which claimed credit on Tuesday for a wave of bombings the day before that killed at least 58 people.

It said the attacks were carried out on behalf of “oppressed Sunnis,” suggesting the group is trying to capitalize on Sunnis’ complaints of being treated as second-class citizens by the Shiite-dominated government.

Attacks on Sunni civilians are rarer but have also been a feature of the surge of bloodletting that has left 3,000 dead since April. More than 730 people have been killed in July alone, according to an Associated Press count, with 563 killed since the start of the Islamic holy month of Ramadan.

The uptick of violence is dampening hopes for a return to normal life nearly two years after the last U.S. forces withdrew from the country.

On Wednesday morning, a carload of gunmen sped through a commercial street in Baghdad’s Shiite-dominated Ur district and opened fire, apparently at random, killing five pedestrians and wounding nine others, a police officer said. In the southeastern suburb of Nahrawan, also a majority Shiite area, drive-by shooters sprayed farmers in a pickup truck with bullets, killing two and wounding three, another police officer said.

In the afternoon, gunmen killed five off-duty soldiers in a drive-by shooting near the city of Mosul, 225 miles northwest of Baghdad. Police said the soldiers were heading to their base when they were attacked.

Also, police said three Sunni anti-al-Qaida fighters were killed when gunmen in a speeding car sprayed their checkpoint with bullets near Hawija, 150 miles north of Baghdad.

The Sunni fighters were members in the militia group known as Sahwa, which joined with U.S. troops to fight against al-Qaida at the height of Iraq war. Ever since, it has been a target for Sunni insurgents who consider them traitors.

Late Tuesday, a suicide bomber set off his explosives among Shiite worshippers leaving a mosque in the city’s suburb of Hussainiya, killing seven. Another bomb struck a Sunni mosque in the ethnically mixed northern town of Tuz Khormato killed four, local police chief Col. Hussein Ali Rasheed said. Four others were wounded.

Medical officials confirmed casualty figures for all attacks. All spoke on condition of anonymity as they were not authorized to release information to reporters.

Al-Qaida’s Tuesday statement also said a campaign called “Breaking the Walls,” which made freeing its imprisoned members a top priority, had come to a close with two attacks on prisons last week that allowed hundreds of inmates, including senior al-Qaida members, to escape. The militant group said it was opening a new campaign called “The Harvest of the Soldiers,” but offered no specifics.