CAIRO – The Egyptian government intensified its crackdown on the Muslim Brotherhood on Wednesday, Dec. 25, formally listing the group as a terrorist organization after accusing it of carrying out a suicide bomb attack on a police station that killed 16 people.

The move marked a major escalation in the army-backed government’s campaign to suppress the Islamist movement that propelled Mohamed Morsi to the presidency 18 months ago but has been driven underground since the army toppled him in July.

It gives the authorities the power to charge any member of the Brotherhood with belonging to a terrorist group, as well as anyone who finances the group or promotes it “verbally, or in writing.”

The Brotherhood condemned the attack on Tuesday in the Nile Delta city of Mansoura, north of Cairo. Earlier on Wednesday, a Sinai-based militant group, Ansar Bayt al-Maqdis, had claimed responsibility for the attack that wounded some 140 people.

In Washington, the State Department also condemned the attack but urged Egypt to have an “inclusive political process.”

“We condemn in the strongest terms the horrific, terrorist bombing yesterday. There can be no place for such violence. The Egyptian people deserve peace and calm,” State Department spokeswoman Jen Psaki said but added: “We also note that the Muslim Brotherhood in Egypt condemned the bombing shortly after it occurred yesterday.

“We are concerned about the current atmosphere and its potential effects on a democratic transition in Egypt,” she added.

The Brotherhood, which estimates its membership at up to a million people, was Egypt’s best organized political force until this summer’s crackdown. A political and social movement founded in 1928, it won five elections after the downfall of President Hosni Mubarak in 2011.

Since Morsi’s overthrow, the state has killed hundreds of his supporters in the streets and arrested thousands more. Morsi and other top Brotherhood leaders were last week charged with terrorism and plotting with foreign militants against Egypt. They could face the death penalty.