A Japanese activist who was briefly held captive in Iraq has sued his own government, saying its decision to send troops to the region angered his kidnappers and was to blame for his ordeal.

Nobutaka Watanabe (search), 35, is seeking the equivalent of $46,000 for mental and physical hardship he suffered during his four days as a hostage, his lawyer Masatoshi Uchida told The Associated Press Wednesday.

"Mr. Watanabe believes his kidnapping was the result of Japan's military presence," said Uchida. "His captors told him that he had been taken because he was from a country that had sent troops to Iraq."

Watanabe, who filed the suit Tuesday, had earlier written dispatches for his activist group from the southern city of Samawah (search), protesting Japan's deployment of some 550 troops there on a humanitarian mission to rebuild infrastructure.

He was taken hostage along with freelance journalist Jumpei Yasuda (search) while traveling near the besieged city of Fallujah on April 14.

The dispatch is Japan's first to a combat zone since World War II. Echoing many critics here, Watanabe claims that the decision to send troops was illegal because it violates Japan's pacifist constitution.

"Mr. Watanabe said he knows from firsthand experience that Samawah is far from being a non-combat zone," as the government claims, said Uchida.

The dispatch was fiercely debated at home, and similar lawsuits questioning the constitutionality of the troop dispatch have been filed at courts across the nation. Kyodo News agency said Watanabe's was the 56th at Tokyo District Court alone.

The government is eager to avoid any trouble that could increase opposition to the mission, but public skepticism has grown as violence has surged, in some cases involving Japanese.

On Wednesday, family members of two Japanese journalists killed in an ambush near Baghdad returned home with the victims' remains.

Shinsuke Hashida — one of Japan's top freelance combat photographers — and his nephew, Kotaro Ogawa, were killed May 27 after unidentified assailants opened fire on their car and it blew up.

Earlier, three other Japanese civilians were also taken hostage, and their kidnappers had threatened to burn them alive unless Japan withdrew its troops.

The government refused and all were released unharmed, but officials were angered by families of the hostages pressuring Tokyo to give in to the kidnappers' demands.

Officials publicly reproached the hostages for ignoring government warnings to stay out of Iraq. All were billed by the government for part of the costs of their travel home.

Watanabe is asking the court to rule that he has no obligation to pay the $193 he has been charged, Uchida said.