On Monday three groups - the New Zealand Palestine Human Rights Campaign, Students for Justice in Palestine, Auckland University, and Students for Justice in Palestine, Waikato University in Hamilton - appealed to the captors to release the peace activists.
Harmeet Singh Sooden and James Loney, both Canadians, were taken with Norman Kember, a Briton, and Tom Fox, an American, on 26 November in Baghdad.
In a statement received by Aljazeera the groups asked the captors to be "merciful and free the men".
The statement read: "[The men] have been supportive of those Palestinian and Iraqi people who to this day suffer injustice and oppression.
"As groups concerned with the plight of Palestinians and Iraqis, we owe it to our friend and supporter Harmeet Sooden, held hostage with three other peace activists, to ask their abductors not to commit an unforgivable crime and harm the innocent.
"Harmeet Sooden is NO spy. He is a peace lover and very supportive of the oppressed Iraqi and Palestinian peoples"
Letter from New Zealand based Palestinian rights groups
"We know Harmeet personally as a fellow university student, a gentle person who regularly joins our rallies and demonstrations in support of the Palestinian and Iraqi people as evident in the attached photo recently taken in Auckland, holding a placard denouncing Israel's Apartheid policies.
"Harmeet Sooden is NO spy. He is a peace lover and very supportive of the oppressed Iraqi and Palestinian peoples."
The Grand Mufti of the Palestinian territories backed this claim, saying the Western hostages were supporters of the Palestinian cause.
Ekrema Sabri said that the four had all been visitors to the occupied West Bank and had taken part in demonstrations against the barrier being built by Israel in the territory.
Ekrema Sabri said the hostages
are supporters of Palestine
"The kidnapping of the four was a surprise to the Palestinian people as they have been supporters of our cause and have stood at our side against the racist separation wall," the Muslim religious leader said at a press conference on Monday.
"It is our duty to support them and to issue a vigorous appeal to the kidnappers to free them so that they can go back to their families and resume their humanitarian work."
The wife of British hostage Norman Kember appealed for his release through Aljazeera on Sunday.
Speaking from London, Pat Kember appealed to her husband's captors to free him and his friends.
"Norman keenly takes care of others," she said.
"He believes that all people should live peacefully. He courageously resists all forms of aggression. He went to Iraq to help Iraqis, stop the widespread violations, identify with the circumstances in which they live and make Iraq a more peaceful place.
Pat Kember appealed on Aljazeera
for captors to free her husband
"I beg you to release Norman and his colleagues so they could continue their work for peace in Iraq. They are friends and allies of Iraqis who want to help you overcome evil by performing good deeds."
Kember, 74, an anti-war campaigner, was in Iraq investigating human rights abuses.
In a message broadcast by Aljazeera on Friday, their captors threatened to kill the hostages by 8 December unless all Iraqi detainees were released.
French engineer kidnapped
In another development on Monday, armed men kidnapped Bernard Planche, a French engineer, from outside his home in west Baghdad.
Planche was hauled away by seven men who arrived in two cars as he prepared to leave his home in the district of Mansur, police quoted witnesses as saying.
Planche was kidnapped from
outside his home on Monday
Planche worked at the Rusafa water treatment plant in eastern Baghdad.
Also on Monday, Germany's Central Islamic Institute appealed to the captors of a German woman abducted in Iraq to set her free.
In a letter to the kidnappers, a copy of which was sent to Aljazeera, the institute said: "If you are Muslims and believers of Islam you should know that to kidnap, hold under detention, haggle over and threaten with killing any person for any reason has been strictly forbidden by the Almighty Allah."
"Your deed is against Allah ... and means disobeying his commandments and disregarding the teachings and the sunnah (practice) of His messenger (peace be upon him) as well."
The letter was signed by Mohammed Salim Abdul Allah, senior director for the body.
Established in 1927, the Institute Islam-Archiv-Deutschland, is the oldest Muslim body in Germany.
Susanne Osthoff was abducted in
Iraq on 25 November
Susanne Osthoff, 43, a convert to Islam, has been missing since 25 November. She had been working as an archaeologist and was abducted along with her driver.
Osthoff has been seen in a video released by her captors, who threatened to kill her and her driver if Germany does not stop co-operating with the US-backed government in Baghdad.