US Secretary of State John Kerry has issued a press statement on the death sentences handed to 529 supporters of the Muslim Brotherhood.

"I am deeply, deeply troubled by the sudden and unprecedented decision by an Egyptian court to issue preliminary death sentences for 529 citizens after a quick mass trial. It simply defies logic", Kerry said.

He urged the "appropriate Egyptian authorities to remedy the situation," adding that the decision does not reflect the values and goals to which the interim government has aspired publicly and privately.

Washington's top diplomat called on the government to revise the ruling and ensure due process for the accused, stating that anything else would "dishonour the bravery of all who sacrificed their lives for democratic values."

Kerry pointed out that it is "impossible to believe that such a proceeding satisfied even the most basic standards of justice."

He noted that most of the defendants were not even in the courtroom.

"The need for due process assumed greater urgency with the start of a new trial for nearly 700 more people in the same courtroom where the earlier judgment was rendered after a two-day summary proceeding in which the defendants were tried as a group rather than on the merits of individual cases," Kerry said.

The 529 defendants were accused of killing Mustafa El-Attar, the deputy commander of the Matay district police station in Minya, during riots in the aftermath of the dispersal of the Rabaa Al-Adawiya sit-in in August 2013. The court acquitted 16 other defendants.

Only 147 defendants were present at the hearing, while the rest are on the run and were tried in absentia, according to Aswat Masriya.

According to state news agency MENA, Morsi supporters were accused of killing the police officer and attempting to murder two others, as well as attacking public property, torching the Matay police station, seizing police weapons and disrupting public order.

The trial began on Saturday with defence lawyers demanding the recusal of the judging panel and its replacement with another "unbiased" panel. Their request was rejected.

On Monday, the court issued its sentence -- the biggest capital punishment verdict in Egyptian legal history -- without hearing the defence arguments.

The defendants' papers will be passed to the grand mufti, the country's official authority for issuing religious edicts, as Egyptian law stipulates that all death sentences be reviewed by him for ratification.

The court has set 28 April for the preliminary verdict to be passed, once the grand mufti pronounces his final say.

The law allows the verdict to be appealed.