Iraq's foreign minister has asked the Iranian ambassador to Baghdad to shed more light on the circumstances surrounding the detention of three Americans caught crossing the border between northern Iraq and Iran.

The case of the three Americans, now in Iranian custody after associates said they had inadvertently stumbled across the border during a hiking trip, has put the Iraqi government in the uncomfortable position of balancing the needs of two close allies who are also mutual antagonists.

Iran has said it is holding the Americans for illegally entering the country, and a prominent Iranian lawmaker has said authorities were investigating whether to charge them with spying. The State Department has dismissed allegations, while Kurdish authorities say the three were just hikers who strayed across the border.

Iraqi Foreign Minister Hoshyar Zebari asked about the detained Americans during a meeting Thursday with the ambassador, according to a statement posted on the ministry Web site.

The statement did not provide details about the conversation, and it was not known whether the ambassador provided any information.

Freelance journalist Shane Bauer, Sara Shourd and Josh Fattal were detained on July 31 after apparently straying across the border while hiking in Iraq's northern Kurdish region.

A fourth American, Shon Meckfessel, who did not go on the hike because he felt ill, has said the three left July 30 to go camping by a waterfall near the border, and that a day later Bauer called him to say they had been detained by Iranian authorities.

Meckfessel has said Bauer urged him to contact the U.S. Embassy.

Iran and Iraq share an 800 mile border over which there have been long-standing disagreements. In the northern mountainous areas especially, the frontier is poorly marked.

The Swiss Embassy in Tehran, which represents U.S. interests, has been trying to learn more about the status of the Americans through its contacts with the Iranian Foreign Ministry.

Iranian lawmakers are scheduled to discuss the case Sunday during the weekly meeting of parliament's foreign policy committee, according to Press TV, the English language Iranian state television.

"We will discuss the additional information (handed to us) and the details of the case," said Hossein Sobhaninia, a member of the commission, in a report on the channel's Web site.

The detentions are the latest problem for relations between Iran and the U.S., which have had no diplomatic ties since 1979 when militant students stormed the U.S. Embassy in Tehran and took Americans hostage for 444 days.

They also come during a period of mounting tension over Iran's nuclear program.

Elsewhere in Iraq, an Iraqi police official said Saturday that death toll climbed to 44 in a suicide truck bomb attack the day before in a suburb north of Mosul.

The rise in the toll made it the deadliest day in Iraq since U.S. soldiers withdrew from urban areas more than a month ago.

Friday's attacks in Mosul as well as others in Baghdad targeted primarily Shiite worshippers and pilgrims across the country, leaving a total of 61 dead and more than 200 wounded.

Funerals were under way in Mosul, while rescuers continued to look for victims possibly trapped under the rubble of the mosque and other buildings that collapsed during Friday's attack, an Iraqi police officer said. The explosion left a 16-foot crater.

The officer spoke on condition of anonymity because he was not authorized to release information to the media.

The Sunni Iraqi Islamic Party denounced the bombings and blamed Iraqi security forces for failing to protect the people. The attacks against Shiite targets have given rise to fears of renewed sectarian conflict, similar to that which nearly tore the country apart in 2006 and 2007.