Former UN nuclear chief Mohamed ElBaradei took his reform campaign outside Cairo as he met with supporters in the northern city of Mansoura on Friday, DPA reported.
A crowd of about 150 people cheered ElBaradei after he finished Friday prayers in the al-Nour mosque, singing the national anthem and waving flags. Supporters also chanted slogans such as "Change", "Raise your voice", "Long live Egypt, long live ElBaradei" and "Mansoura is with you."
"I came to show the government that we are not moving a step backward," Omar Saleh, 23, told the German Press Agency dpa.
Saleh, who travelled from Cairo to support ElBaradei, also said he came to tell the government that "there is an alternative to Hosny Mubarak."
Mubarak, the Egyptian president, has been in power for nearly 30 years and has vowed to continue serving until his "last breath."
Last year, ElBaradei said he would consider running for the presidency only if a fair vote is guaranteed. His announcement was welcomed by opposition and youth activists, who started campaigning for him online.
When the Nobel Peace Prize winner had previously returned to Egypt for a brief visit in February, more than 1,000 supporters welcomed him at the airport.
Adel al-Ganayni, a member of the Muslim Brotherhood, said he joined the crowds on Friday to express his support for ElBaradei.
The Muslim Brotherhood, Egypt's largest opposition group, has not declared its support for ElBaradei.
Hassan al-Fotouh, 30, said he would rather like to see the Brotherhood take power and does not support ElBaradei.
"If the Brotherhood got into power, that would be the best thing because ElBaradei is with the United States," he told dpa.
"We need someone to speak strongly about Palestine and not be afraid like Mubarak and ElBaradei," he added.
Since his return to Egypt in March, ElBaradei has been meeting with politicians, activists, celebrities and religious leaders in hopes of pressuring the government to pass political reforms.
The opposition groups that have rallied around ElBaradei last month called on the government to institute seven reforms that the coalition said would provide for more free elections.
Those reforms include imposing a two-term limit on the Egyptian presidency, instituting judicial oversight over elections and loosening restrictions on who may run for president.
Amendments to Article 76 of the Egyptian constitution that were passed in 2007 require presidential candidates to have been a member of a legal party's senior leadership for at least a year, or to secure the nomination of 250 local and national elected officials.
ElBaradei has held no senior position in a party.
The ruling National Democratic Party (NDP) has an overwhelming majority in Egypt's elected institutions, making it difficult for an independent candidate to run for the presidency without the NDP's blessing.
Mubarak said last month that ElBaradei was welcome to stand in presidential elections - as long as he respected the constitution.
"We don't need new heroes," Mubarak said. "If (ElBaradei) wants to join a party, he can choose any party. If he wants to (be a) candidate via a party, he can go ahead. We just have a constitution which needs to be respected."
Organisers from the ElBaradei coalition said that a petition for his candidacy has been endorsed by some 25,000 people throughout Egypt, adding that more people were still signing it.
One man from Mansoura was surprised by ElBaradei's visit on Friday and went to cheer him on. He also signed the petition.
No riot police were seen in Mansoura, but Mohamed Sahsah, a 55- year-old engineer, told dpa that thugs had prevented ElBaradei from going to a bigger mosque for prayers earlier on Friday.
"The regime is trying to silence people because Elbaradei has brought hope for change," Sahsah said.