The top bomb-maker for Abu Musab al-Zarqawi (search) has been killed in Fallujah, Fox News learned Monday.

The bomb-making lieutenant, whose name wasn’t released, died in a gun battle at a terrorist safe house late last week, military sources told Fox.

The military officer's death is significant because Al-Zarqawi is the man believed to have masterminded a number of recent attacks against the coalition in Iraq.

Civil affairs soldiers were passing out election pamphlets in Fallujah, just west of Baghdad, when someone began shooting from a nearby house, sources told Fox. That’s when Task Force 121 (search), part of U.S. Special Forces, was called in.

After a short gun battle, two people were killed — including the Zarqawi lieutenant and one of the soldiers passing out the brochures. A handful of others were captured.

Inside the terrorist safe house, sources said the military found a passport belonging to Zarqawi, fake identification and other information.

In another weekend raid — this one initiated by American troops over the weekend in Baghdad — a detailed map of U.S. headquarters turned up in the Iraqi capital, military sources told Fox.

The sources said a terrorist cell is believed to have been using the map of Camp Victory (search) to plan an attack there. Sources told Fox they suspect an Iraqi contractor is helping terrorists, and they've launched a full investigation into who the culprit might be.

Meanwhile, defense officials say that a copy of a letter believed to have been penned by Zarqawi has turned up in Saudi Arabia. The copy was discovered with Saudi financiers whom Defense officials believe were being solicited to fund terrorist operations inside Iraq, sources told Fox.

The U.S. military recently intercepted the original from Al Qaeda member Hassan Ghul (search). The letter is significant because of its message to the terrorist network's command structure in the mountains along the border between Afghanistan and Pakistan calling for help in Iraq. Defense officials told Fox they are convinced that there is a communications link — a sharing of tactics — among Al Qaeda-tied groups in Iraq and Afghanistan.

In another find that could prove the Afghanistan-Iraq connection, three Afghans were arrested over the weekend as they entered Iraq from Turkey carrying tens of thousands in U.S. dollars and large quantities of Iranian currency, military sources told Fox.

American soldiers have recovered millions of U.S. dollars in recent weeks inside Iraq — crisp, new bills that officials believe came directly from an unidentified bank.

Fox News' Bret Baier, Catherine Donaldson-Evans and Geraldo Rivera contributed to this report.