Cairo: “Down with the military’s rule!” chant a group of young men aboard a carriage on a Cairo subway train.

“Down with the guide’s rule,” retort a rival group on the same couch, referring to the chief of the Muslim Brotherhood locked in a deepening crisis with the country’s military-installed government.

The rivalry soon degenerates into a fist fight in a fresh reminder of the country’s deepening polarisation. Egypt has been increasingly divided and experienced deadly violence since the army toppled president Mohammad Mursi of the Brotherhood last month after large protests against his one-year-old rule.

“I am not a Brother, but no one with a clear conscience and fears God will accept that the people are killed like flies,” said Hussam Mokhtar, an engineering student.

“The police, backed by the army, were brutal in ending the vigils in Raba’a and Al Nahda. Do you call this a humanitarian act?”

Around 600 people were killed and thousands wounded on Wednesday in security forces’ internationally condemned crackdown on two pro-Mursi protest camps in north-east and south of Cairo.

The swoops triggered street violence and clashes between police and Brotherhood’s followers. The caretaker government said the weeks-long vigils had posed a threat to national security, accusing the protesters of using firearms against police during the evacuations.

The Brotherhood charged that the police by using force committed a “disgraceful massacre” and vowed to persist protesting until Mursi is restored to power.

“The Brotherhood is determined to plunge the country into a sea of blood,” said Hanafi Sadallah, a government employee.

“They cannot digest their removal for power despite their glaring failure. The state must show more toughness in controlling the Brothers, who know only the language of violence.”