BAGHDAD — Seeking to normalize life in the embattled capital, Iraq’s prime minister said on Thursday that the authorities would lift a nighttime curfew in Baghdad that has been in force, with some interruptions, for over a decade.

The prime minister, Haider al-Abadi, also barred unauthorized gunmen from entering four Baghdad neighborhoods and ordered the removal of checkpoints from some roads, seeking to counter the atmosphere of armed siege that has persisted in the city since the United States invasion in 2003.

Mr. Abadi’s spokesman, Rafid Jaboori, said the order to lift the curfew came after diminishing threats to Baghdad since the summer, when there had been fears that it would be overrun by the Islamic State, which seized parts of northern Iraq beginning in June. It was also an effort by Mr. Abadi to make good on pledges to “make life easier for Iraqis in liberated areas,” Mr. Jaboori said.

The dangers, however, have persisted. At least 26 people have been killed in bombings in the past week, including from car bombs that went off in a busy market. The United Nations said this week that at least 256 civilians were killed last month in the Baghdad governorate, which includes areas beyond the capital’s heavily reinforced security checkpoints.