The worker was killed in the suspected resistance attack targetting the Supreme Assembly for the Islamic Revolution in Iraq (SAIRI).
Mortar shells slammed into the party’s office, killing Khalil Karam Hasnawi, 29, and wounded a second person, said SAIRI’s chief Izz al-Din Musa in Kirkuk.
“The goal of these attacks is to wreck the future of Iraqis and disturb security,” he said in the oil-rich town, 255km north of Baghdad.
Musa claimed the attacks were carried out by al-Qaida. US occupying forces and Shia groups in Iraq regularly blame incidents on al-Qaida and Baathist elements.
SAIRI’s leader Ayat Allah Muhammad Bakr al-Hakim was killed in August along with about 83 civilians in a car bombing in Najaf.
SAIRI is represented on the US-appointed Iraqi Governing Council, a move which has angered both Sunnis and Shias in post-Saddam Hussein Iraq.
Meanwhile, US military occupation officials said a soldier was killed and a second wounded late on Monday near the flashpoint town of Ramadi, 110km west of the capital.
Foreign ministry attacked
Also on Tuesday an explosion hit the foreign ministry building in Baghdad and gunfire was heard in the area, reported an AFP correspondent.
The compound is near a US military base.
"One mortar hit inside the compound," said Police Captain Ali
Khadim. "There were no casualties."
Khadim said the bomb landed inside the complex, but did not hit the ministry building.