BAGHDAD >> Iraqi authorities said Tuesday that they’ve arrested a man suspected of killing a prominent Shiite official who was responsible for purging loyalists of deposed ruler Saddam Hussein. The official was once implicated in a bombing that killed Americans.

Gunmen shot and killed Ali al-Lami late Thursday in the Iraqi capital. Al-Lami headed a committee tasked with rooting out members of Saddam Hussein’s ruling Baath Party and barring them from important government jobs. He was the latest victim of an assassination campaign across Iraq that has killed scores of political and governmental figures.

Al-Lami’s death immediately led to cries that ex-Baathists were behind his killing, although inter-Shiite rivalries have also shown a tendency to spill out into violence on the streets.

A statement by the Baghdad Operations Command posted Tuesday on their website said the suspect was a member of the security forces during Saddam’s regime. He was arrested in the city of Taji, 12 miles (20 kilometers) north of Baghdad, the statement said.

The Baghdad Operations Command provided no further details, and officials did not answer repeated requests for comment. Iraqi security officials have been under intense pressure to find al-Lami’s killer and demonstrate that they are capable of protecting the country and its senior leaders.

A spokesman for Baghdad police, Lt. Col. Mushtaq Talib, said officials would hold a press conference on Wednesday but declined to give more details.

Al-Lami was arrested by U.S. and Iraqi forces in 2008 for suspected ties to Iranian-backed Shiite militias, and was accused by U.S. officials of being involved in a bombing that killed eight people, including two American soldiers and two State Department employees.

His arrest reinforced suspicions about Tehran’s influence within the Shiite-led Iraqi government. Al-Lami denied the charges but was never formally exonerated.

His role last year in trying to oust hundreds of Sunni candidates from running in the parliamentary election due to alleged ties to the Saddam regime fueled criticism that Iraqi Shiites, backed by Iran, were trying to sideline Sunnis from power and threatened to re-ignite sectarian tensions.