The United States expressed "deep concern" Sunday after an Egyptian court sentenced deposed Islamist president Mohamed Morsi and more than 100 others to death for their role in a mass jailbreak during the 2011 uprising.

"We have consistently spoken out against the practice of mass trials and sentences, which are conducted in a manner that is inconsistent with Egypt's international obligations and the rule of law," a State Department official said.

Noting that they were preliminary sentences, the official added: "We continue to stress the need for due process and individualized judicial processes for all Egyptians in the interests of justice."

Many of those sentenced on Saturday were tried in absentia. The court will pronounce its final decision on June 2, since under Egyptian law, death sentences are referred to the mufti, the government'sinterpreterof Islamic law, who plays an advisory role.

Defendants can still appeal even after the mufti's recommendation.

Morsi, elected president in 2012, ruled for only a year before mass protests spurred the military to overthrow him in July 2013.

He was among dozens of Islamist leaders detained amid a crackdown that left hundreds of Morsi supporters dead.

Morsi, sitting in a caged dock in the blue uniform of convicts having already been sentenced to 20 years for inciting violence, raised his fists defiantly when the verdict was read.

Hours after the ruling, gunmen shot dead two judges, a prosecutor and their driver in the strife-torn Sinai Peninsula, in the first such attack on the judiciary in the region.

The US State Department official said they had been "senselessly murdered."

"We reiterate our steadfast commitment to Egypt's security," the official added.