A U.S. Justice Department report says Federal Bureau of Investigation agents raised concerns about controversial interrogation techniques other U.S. agencies used on terror suspects.

The report, issued Tuesday, describes frequent clashes between the FBI and the military and Central Intelligence Agency over interrogation methods used in Afghanistan, Iraq and Guantanamo Bay, Cuba.

It says the FBI raised concerns about questionable tactics including the use of snarling dogs and forced nudity.

The study commends FBI agents for avoiding participation in detainee abuse.  But, it blames the bureau for not providing clearer guidance for how agents should confront interrogators operating under different rules.

In one instance, the government agencies clashed over the treatment of senior al-Qaida figure Abu Zubaydah.  The CIA has confirmed it used a simulated drowning technique on Zubaydah and two other detainees.

Simulated drowning, also called "waterboarding," has been at the center of debate on the legality of the interrogation tactics.

Critics of the technique say it amounts to torture.

Some information for this report was provided by AFP, AP and Reuters.