The military tribunal of a Yemeni man held at the US naval base at Guantanamo Bay in Cuba has resumed.

Ali Hamza al Bahlul is alleged to have been a bodyguard for Osama bin Laden, and to have made propaganda videos for al-Qaeda.

He refused to be represented by a US lawyer at the trial. The dispute over his representation was expected to take up most of the hearing today.

A separate panel will start hearing the case of 19-year-old Canadian national Omar Ahmed Khadr. He was 15 when captured in Afghanistan accused of throwing a grenade which killed a US army medic.

Both men are the latest of only a handful of prisoners at Guantanamo to begin what is called a military tribunal - a legal process set up by the Bush administration to deal with terrorist suspects.

In November, the tribunal of another detainee was halted when lawyers secured a Supreme Court hearing of the case. This will take place in March.

The tribunals are presided over by a panel of military officers but do not come under US or international law.

They can impose penalties of life imprisonment or death. The 500 or so prisoners at Guantanamo are now entering their fifth year of captivity.