The discovery, which underlined the vulnerability of would-be police officers to attack, came as political parties started appealing results from last month's general election amid continued complaints of fraud.
The bodies of the men, part of a group of 35 police volunteers who went missing on Monday evening, were found on open land near Nibaie, a few miles north of the capital. Their hands were bound and they had been shot.
The men had gone from Samarra, 125 kilometres north of the capital, to Baghdad to join the police force, but had been turned down and were heading back home.
Hostage appeal
A Jordanian held hostage in Iraq said in a videotape aired on al-Arabiya television that his captors had wrapped him in an explosive belt and set a four-day deadline to execute him unless their demands are met.
"I appeal to the Jordanian government not to ignore my issue because my life is in danger, as the deadline for my life sentence has been extended by four days," said the hostage, identifying himself as Mahmud Salman Saaidiyat.
"I am in great danger, the area is full of mines and I am wearing an explosive belt and I do not know when my last hour will come," said the hostage, wearing prescription glasses as he was reading a statement.
The man, a driver for the Jordanian ambassador to Iraq, was snatched in south Baghdad on December 20.
This was the fourth time that his captors have extended the deadline to execute him, saying he will die unless an Iraqi woman, Sajida al-Rishawi, is freed from prison where she has been held since hotel bombings in Amman in November.
The tape came amid increasing concern about abducted US reporter Jill Carroll, whose kidnappers have threatened to kill her unless US forces released all Iraqi women held in prison.
A justice ministry official said six Iraqi women detainees would be released by the US military within a week.
Deadly violence flared on Sunday, with 11 people killed, including policemen and a Shiite municipal leader and four children.
Political scramble
Meanwhile Iraq's political parties have two days to appeal the release Friday of final but uncertified results from the December 15 poll, the first to choose a permanent parliament following the ouster of Saddam Hussein in 2003.
The ensuing weeks are also expected to witness lengthy and complex negotiations to form a government to rule the country for the next four years, a process observers say could take at least two months.
"Today the (judicial) commission begins receiving appeals, and will continue doing so until late tomorrow," said electoral commission member Abdel Hussein al-Hindawi.
All the main parties have complained about the results, including the
Shiite religious-based United Iraqi Alliance which topped the poll and won 128 of parliament's 275 seats.
The Alliance believes it should have won six to nine seats more, the
Kurdish Alliance which won 53 seats believes it should have got four more, while the main Sunni Arab coalition, the National Concord Front, which won 44 seats says it was cheated of 11 more.