BAGHDAD (AP) — A string of bombings targeting Shiite mosques in Iraq killed at least 23 people and wounded dozens today, officials said. The attacks were the latest in spectacular assaults staged by insurgents seeking to undermine the Shiite-led government’s efforts to achieve security across the country.

There was no immediate claim of responsibility, but the bombings bore the hallmarks of al-Qaida’s Iraq branch. The group, known as the Islamic State of Iraq, frequently uses car bombs, suicide bombers and coordinated blasts in an effort to sow fear among Shiites and erode their trust in the government of Prime Minister Nouri al-Maliki.

Four car bombs hit Shiite mosques in the Iraqi capital as worshippers were leaving after Friday prayers, killing 19 people and wounding 72.