"We will always be non-violent and peaceful. We remain strong, defiant and resolved," Brotherhood spokesman Gehad El-Haddad wrote on his Twitter account. "We will push (forward) until we bring down this military coup," he said.
At least 421 people were killed and more than 3,500 injured during clashes in the country yesterday after security forces evicted supporters of Morsi from two protest camps, the health ministry said, according to the state-run EGYNews site. Those killed included 43 police officers, the interior ministry said.
The Muslim Brotherhood claimed that more than 2,000 people had been killed in the violence. Egypt's army-backed interim Prime Minister defended the deadly operation by security forces against supporters of Morsi camped at Rabaa al-Adaweya and al-Nahda.
In a televised statement yesterday, Hazem el-Beblawi said the decision to break up the protests "was not easy" and came only after the government had given mediation efforts a chance. "We found that matters had reached a point that no self respecting state could accept," he said, citing what he describes as "the spread of anarchy and attacks on hospitals and police stations".
Bulldozers were said to have been used to uproot the camps and drive out the protesters who were seeking Morsi's reinstatement after the 62-year-old Islamist was ousted by the military on July 3.
The government yesterday imposed a month-long emergency after riot police backed by armoured vehicles, bulldozers and helicopters swept away the two encampments of pro-Morsi supporters. Security forces shot dead scores of people in their assault on the camps, defying international pleas to show restraint after a six-week stand-off with Morsi's Muslim Brotherhood supporters, Al Jazeera news channel reported.
Vice-President Mohamed ElBaradei resigned yesterday, saying peaceful means could still have been found to end the confrontation, but other members of the government have rallied behind the decision to use force.