(CNN) -- Streets in major Egyptian cities appeared calm Saturday, a day after clashes erupted between security forces and opposition supporters, state media and eyewitnesses said.
The clashes with the country's biggest opposition bloc come ahead of November 28 parliamentary elections.
Police used tear gas and rubber bullets, and arrested tens of Muslim Brotherhood supporters, local media reported.
There was no official confirmation on how many people were arrested, but the Muslim Brotherhood website put the number at more than 270.
In Alexandria, 33 people were injured as demonstrators threw rocks at security forces trying to disperse a crowd from one neighborhood, eye witnesses said.
Various opposition groups -- including the banned Muslim Brotherhood group, whose candidates are forced to run as independents -- have accused the ruling National Democratic Party (NDP) of using its power to suppress voices critical of President Mubarak's almost-30-year rule.
The ruling party has dismissed the accusations.
Opposition calls for internationalal election monitors are unnecessary, said the ruling party general secretary, Safwat al-Shareef.
Egypt's Supreme Election Committee and "civil community groups will guarantee free and transparent elections, Al-Shareef said.
The election commission said that 76 Egyptian civil organizations will be allowed to monitor the polls, but the paperwork is not finished, official news agency MENA reported Friday.
About 800 candidates from the ruling party, 250 from the liberal al-Wafd Party and 130 from the Muslim Brotherhood are running for the parliament's 508 seats.
Smaller parties and opposition movements have declared they are boycotting the elections over transparency concerns.