CAIRO/BERLIN — Authorities in an Egyptian city scaled back a curfew imposed by President Mohamed Morsi, who cut short a visit to Europe on Wednesday to deal with the deadliest violence in the seven months since he took power.

Two more protesters were shot dead before dawn near Cairo’s central Tahrir Square on Wednesday, a day after the army chief warned that the state was on the brink of collapse if Morsi’s opponents and supporters did not end street battles.

More than 50 people have been killed in the past seven days of protests by Morsi’s opponents.

Morsi imposed a curfew and a state of emergency on three Suez Canal cities on Sunday but that only seemed to further provoke crowds in a week of unrest marking the second anniversary of the uprising that toppled Hosni Mubarak.

The governor of Ismailiya, one of the three canal cities, said on Wednesday he was scaling back the curfew, which would now take effect nightly from 2:00am instead of 9:00pm.

Morsi, speaking in Berlin before hurrying home to deal with the crisis, called for dialogue with opponents but would not commit to their demand that he first agree to include them in a unity government.

Asked about that proposal, he said the next government would be formed after parliamentary elections in April.

Egypt was on its way to becoming “a civilian state that is not a military state or a theocratic state”, Morsi said.

The violence at home forced Morsi to scale back his European visit, billed as a chance to promote Egypt as a destination for foreign investment. He flew to Berlin but called off a trip to Paris.

Chancellor Angela Merkel, who met him, echoed other Western leaders who have called on him to give his opponents a voice.

“One thing that is important for us is that the line for dialogue is always open to all political forces in Egypt, that the different political forces can make their contribution, that human rights are adhered to in Egypt and that of course religious freedom can be experienced,” she said at a joint news conference with Morsi.

Near Cairo’s Tahrir Square on Wednesday morning, dozens of protesters threw stones at police who fired back tear gas, although the scuffles were brief.

Opposition politician Mohammed El Baradei called for a meeting of the president, ministers, the ruling party and the opposition to halt the violence. But he also restated the precondition that Morsi first commit to seeking a national unity government.

The worst violence has been in the Suez Canal city of Port Said, where rage was fuelled by death sentences passed against soccer fans for roles in deadly riots last year.

Egypt’s main liberal and secularist bloc, the National Salvation Front, has so far refused talks with Morsi unless he promises a unity government including opposition figures.

“Stopping the violence is the priority, and starting a serious dialogue requires committing to guarantees demanded by the National Salvation Front, at the forefront of which are a national salvation government and a committee to amend the constitution,” Baradei said on Twitter.

Those calls have also been backed by the hardline Islamist Al Nour Party — rivals of Morsi’s Muslim Brotherhood. Nour and the front were due to meet on Wednesday.

Brotherhood leader Mohammed El Beltagy dismissed the unity government proposal as a ploy for the front to take power despite having lost elections. On his Facebook page he ridiculed “the leaders of the Salvation Front, who seem to know more about the people’s interests than the people themselves”.

In a sign of the toll the unrest is having on Egypt’s economy, ratings agency Fitch downgraded its sovereign rating by one notch to B on Wednesday.