BAGHDAD (AP) – Two truck bombs struck separate communities north of Iraq’s capital on Saturday, killing at least 16 people in the latest attacks to indicate that insurgents are targeting relatively unprotected areas.

Iraqi security forces have focused on defending cities after the withdrawal of U.S. combat troops from urban areas nearly two months ago. But a recent series of high-profile bombings has killed hundreds in remote areas as well as cities and has raised concerns Iraqi forces are not up to the task of protecting the population.

Saturday’s deadliest attack came at about 8 a.m. when a suicide truck bomber attacked a small police station in the remote village of Hamad north of Baghdad, killing at least 12 people, including six police, said officials from the Iraqi army and police.

Police attempted to stop the truck, opening fire and forcing the attacker to change direction and slam into a concrete barrier near a market, they said. The blast damaged the police station and a number of nearby homes and shops, the officials said. Fifteen people were also wounded in the attack, said the police official.

Hamad is a primarily Sunni village on the edge of Shirqat, a town between Saddam Hussein’s hometown of Tikrit and Mosul, which the U.S. military considers to be the last urban stronghold of al-Qaida in Iraq.

Iraqi police defused a car bomb in the same area three days earlier, said Shirqat’s police chief, Ali al-Jubouri. “I think this attack is in retaliation for what we did,” he said.

The second attack targeted a market near Mosul in the city of Sinjar. A parked truck bomb that exploded at about 10:15 a.m. killed at least four people and wounded 23 others, police said.

A double suicide bombing earlier this month in Sinjar devastated a cafe packed with young people in northwestern Iraq, killing at least 21 people.

The city, which is dominated by members of the Kurdish-speaking Yazidi religious minority, was also hit by four suicide truck bombers nearly simultaneously, killing as many as 500 Yazidis, on Aug. 14, 2007.

Iraqi forces have stepped up security in Baghdad and other cities in Iraq since an Aug. 19 double suicide truck bombing in the Iraqi capital that targeted the foreign and finance ministries. About 100 people were killed. But remote villages often depend on a small security force for protection. Bombers have been exploiting that vulnerability in villages surrounding Mosul, mainly targeting ethnic minorities.

While there were no immediate claims of responsibility for Saturday’s attacks, suicide vehicle bombings are the hallmark of al-Qaida in Iraq. A front group for the terrorist organization has claimed responsibility for the recent ministry bombings.

Iraq has demanded Syria hand over two suspects wanted in those bombings, raising tension between the two countries that led each side to recall their respective ambassadors. “We are dealing with the crisis, containing it and preventing any further escalation or tension,” Iraqi Foreign Minister Hoshyar Zebari said Saturday during a news conference with Iranian Foreign Minister Manouchehr Mottaki.

Mottaki said Iran would work with both countries, who are its allies, to resolve the tension.

“We will spare no efforts to offer support,” he said.

Zebari said Iraq’s government plans to ask the United Nations to back the creation of an international court to try those accused in the Baghdad bombings.

Saturday’s attacks came as thousands of mourners gathered in the streets of the holy city of Najaf, south of Baghdad, for the arrival of the body of Abdul-Aziz al-Hakim, one Iraq’s most powerful Shiite leaders, who died Wednesday of lung cancer in Iran.

The casket’s arrival ended a three-day mourning tour through Iran, Baghdad and other portions of Iraq’s Shiite heartland. The Iranian foreign minister attended the burial.

Al-Hakim led the Iranian-backed Supreme Islamic Iraqi Council, Iraq’s largest Shiite party, and was widely revered for helping pave the way for the re-emergence of Shiite power after decades of oppression under Saddam Hussein’s Sunni-led regime.

The wooden coffin was buried next to al-Hakim’s brother, Ayatollah Mohammed Baqir al-Hakim, who led the party until he was killed in a car bombing in Najaf soon after the brothers returned to Iraq in 2003 after years in exile.

In his will, al-Hakim called for peaceful coexistence among Iraq’s fractured sects, warning that national unity was being targeted by Saddam loyalists and Sunni extremists.

“They see that the only way to achieve their victory is by creating sedition between Iraqi Shiite and Sunnis,” he said in the will, which was read by his son and anointed successor, Ammar, at the funeral service. He also urged Iraqis to vote in January’s parliamentary elections, which are likely to be bitterly contested between his party and a rival faction led by Prime Minister Nouri al-Maliki.

Also Saturday, Kurdish authorities distributed 850,000 copies of a proposed constitution along with food rations in Sulaimaniyah, one of three provinces in the Kurds’ northern self-ruled region. The move is seen as a step in reviving a referendum on the constitution that Iraq’s election commission prevented from occurring in July.

Arabs see the draft constitution as an effort by Kurds to expand their region, escalating tension between the two groups that is seen as a major threat to Iraqi stability.