BAGHDAD — In the deadliest day of violence since the withdrawal of most U.S. troops from Iraq's cities last week, at least 54 people were killed in bombings Thursday in Baghdad and other locations.
Prime Minister Nouri Maliki has warned that various armed groups will try to discredit Iraq's security forces and cause instability as American troops pull back. The majority of U.S. troops left their bases in the cities June 30, in accordance with a security agreement signed by officials late last year.
The worst attack Thursday occurred in Tall Afar in Nineveh province in the north, where a double suicide bombing killed 34 people, prompting a senior Iraqi official to express concern that the country's security forces, now fully responsible for protecting the cities, had been penetrated by armed groups.
In Baghdad, a pair of roadside bombs killed at least seven people in the Shiite district of Sadr City, police said. In the capital's Sunni district of Adhamiya, roadside bombs killed 13 people, with one blast targeting a police patrol.
Militants appear focused on the north, where Arabs and Kurds are locked in a dispute over a 300-mile stretch of land where Saddam Hussein's regime expelled Kurds and settled Arabs in their place. Iraq's semiautonomous Kurdish region wants to annex those areas, an idea Arabs oppose.
The quarrel is complicated by the valuable oil reserves in Kirkuk province, which all sides want. Concerns have grown that the tensions, if left to fester, could flare into a Kurdish-Arab war.
Provincial council member Yahya Abed Majoub, a member of the Sunni Arab Iraqi Islamic Party, blamed the attack in Tall Afar on political factions as well as neighboring countries.
"There are groups who want to ignite sectarian and ethnic tensions all over Iraq. Nineveh is just the starting point," Majoub said. "There is a political agenda from inside and outside related to the election."
Kurdish officials blamed the attack on the group Al Qaeda in Iraq. They lashed out at the U.S. military, however, saying it had allowed security to deteriorate by withdrawing. The Kurds have viewed the American forces as a partner and a check on Arab ambitions in the provinces adjoining Iraqi Kurdistan.
Across the north, the Kurdish parties that until last year dominated political life in Nineveh and Kirkuk have been disturbed by the rise of Arab parties in provincial elections and an aggressive stance from Baghdad.
Kurdish officers have been transferred out of Iraqi army units in Kirkuk and Nineveh. De facto stalemates exist in both places, where Arab-controlled Iraqi army units hold large swaths of land and Kurdish peshmerga forces also control chunks of terrain. Kurdish officials say the U.S. military has shown a bias toward Arabs.
"There is a vacuum that has been created between Tall Afar and Mosul after the withdrawal of U.S. forces. Baathists and Qaeda activities have resumed," said Harem Kamal Khurshed, head of the Patriotic Union of Kurdistan party in Mosul. "I think the terrorist attacks will increase. The attacks of Qaeda will increase because the Iraqi army is not capable and cannot control security completely."
U.S. military officials have said they expect attacks such as those Thursday. The overall trend for violence, however, continues to be downward, despite some spikes.
Continuing violence could pressure U.S. officials to rethink their deployment strategy, but the security agreement with the Iraqis limits changes the U.S. can make. Under the accord, American troops cannot enter Iraqi cities without the permission -- and escort-- of Iraqi forces. In lieu of access to neighborhoods, military commanders hope to prevent violence by disrupting cells outside the cities and intercepting weapons.
After Thursday's blast, Nineveh officials warned that political groups were involved in the attacks and they predicted a steady rise in bloodshed before national elections in January.
The Tall Afar bomber, dressed like a police officer, entered the house of a counter-terrorism soldier at 7 a.m. in a heavily guarded district, just outside the city's government center. He then blew himself up, killing the soldier, his wife and some of their children, according to Nineveh's governor, Atheel Najafi.
As relatives and neighbors rushed into the building to pull out the wounded and dead, a second bomber struck, Najafi said. Witnesses described wounded men, women and children lying in rubble alongside bodies that had been torn apart by the blasts.
Najafi questioned how the first attacker was able to disguise himself as a police officer and proceed unstopped.
"I have ordered a probe into this incident focusing on the security forces," the governor said. "It is well known the security forces are infiltrated. We think it is the right time to reform them."
Najafi, who has been enmeshed in a feud with the main Kurdish parties in the north, accused political elements of being involved in the attack in an attempt to keep U.S. troops bogged down in Nineveh.