BAGHDAD - A string of attacks killed at least 16 people in Iraq on Saturday, while gunmen abducted eight policemen guarding a post on the country's main highway to Jordan and Syria, the latest in a wave of violence to grip the country.

The shootings and bombings follow three days of attacks that killed 130 people in both Shiite and Sunni areas in scenes reminiscent of retaliatory attacks between the two groups that pushed the country to the brink of civil war in 2006-2007. The spike in bloodshed in recent weeks has raised fears the country may be heading toward a new round of sectarian conflict.

Tensions have been worsening since Iraq's minority Sunnis began protesting what they say is mistreatment at the hands of the Shiite-led government, including random detentions and neglect. The mass demonstrations, which began in December, have largely been peaceful, but the number of attacks rose sharply after a deadly security crackdown on a Sunni protest camp in northern Iraq on April 23.

Majority Shiites control the levers of power in post-Saddam Hussein Iraq. Wishing to rebuild the nation rather than revert to open warfare, they have largely restrained their militias in the past five years or so as Sunni extremist groups such as al-Qaida have frequently targeted them with large-scale attacks. But the sharp jump in attacks on Sunni areas, including bombings on Friday that killed at least 76 people, has fueled concerns of renewed retaliatory killings.

In Saturday's deadliest attack, gunmen broke into the house of an anti-terrorism police captain in the southern suburbs of Baghdad, killing the officer and his family in their sleep. Police officials identified the dead as Cap. Adnan Ibrahim, his wife and two children, aged eight and 10.

The attackers fled the scene, and killed another policeman who tried to stop them at a nearby checkpoint.

Meanwhile in the western Sunni province of Anbar, gunmen kidnapped eight policemen who were guarding a post on the main highway linking Iraq to both Jordan and Syria, according to two police officials.

Earlier in the day, security forces and gunmen clashed in the area after police tried to arrest a Sunni tribal sheik suspected of being behind the killing of three army intelligence soldiers stopped by gunmen near a protest site in the city of Ramadi last month. Iraqi authorities had offered a bounty for the arrest or information leading to the arrest of the sheik, Khamis Abu Risha, and two other people they say were linked to the killings.

The fighting near Abu Risha's house north of Ramadi left three people wounded. No arrests were made. Later, gunmen deployed near the main entrance of Anbar Operations Command headquarters in Ramadi, 115 kilometers (70 miles) west of Baghdad.

Hours later, Ramadi police said a bomb placed under stalls in a small stadium exploded, killing four people who were watching a local soccer match.

Shortly before sunset, a car bomb went off near a small market in in the town of Latifiyah south of Baghdad, killing three people and wounding 12.

Elsewhere, in the predominantly Shiite city of Basra in southern Iraq, gunmen shot and killed a Sunni cleric, Assad Nassir, as he was leaving his house, police said.

Two Iraqi soldiers were also killed and two others wounded when a roadside bomb struck a group of soldiers arriving to inspect the scene of a blast that took place earlier in the northern city of Mosul.

A security official said a roadside bomb hit a police patrol in the northern suburbs of Baghdad, killing one policeman and wounding two others.

Health officials confirmed the death tolls. All officials spoke on condition of anonymity because they are not authorized to talk to the media.