CAIRO -- Two protesters were killed in clashes in Egypt between Islamist demonstrators and their opponents after midday prayers Friday, the final day of campaigning ahead of next week's presidential election, authorities said.
The Health Ministry said one person was killed in Cairo and another in the oasis town of Fayoum, about 50 miles southwest of the Egyptian capital. At least 23 people were wounded, the ministry added.
The violence came on the last day of campaigning for the May 26-27 presidential race, in which former army chief Abdel-Fattah el-Sissi is widely expected to defeat leftist politician Hamdeen Sabahi.
In the northern Cairo district of Matareya, violence broke out during a protest by Muslim Brotherhood supporters, security officials said, speaking on condition of anonymity in line with regulations.
The officials said that some anti-Brotherhood residents opened fire at the Islamist rally, but several protesters claimed the shots were fired by security forces dressed in civilian clothes, based on the type of weapons used in the shooting.
The protesters spoke on condition of anonymity, fearing for their own safety. The claim could not be independently confirmed.
Egyptians will vote on Monday and Tuesday for their next leader following the overthrow of Islamist president Mohamed Morsi last summer.
The previous presidential vote in 2012 -- the first since the uprising that overthrew longtime autocrat Hosni Mubarak the year before -- saw fierce competition from among 13 candidates and two rounds of voting from which Morsi emerged as the winner.
Morsi was overthrown by the military, at the time led by el-Sissi, after millions of Egyptians took to the streets to denounce his turbulent yearlong rule.
On the last day of campaigning, both candidates made a final appeal to Egyptians to vote.
In a televised interview aired on a number of channels, el-Sissi called on people to head to the polls in larger numbers than the mass protests that preceded Morsi's ouster.
"We need you more than any other time in history, because this is a breakthrough point," he said.
Sabahi meanwhile appeared in an open square near downtown Cairo among his supporters, where he vowed to secure more freedoms and social justice.
Elsewhere in Egypt, suspected Islamic militants blew up a natural gas pipeline in Arish city, in the restive Sinai Peninsula.
Officials said assailants planted explosives under the line feeding several plants, including one owned by the armed forces.
The attack came a day after the top leader of a Sinai-based al-Qaida-inspired group and three of his associates were killed in a drive-by shooting in the volatile peninsula bordering Israel and the Gaza Strip, dealing a heavy blow to the militant group.
Shadi el-Manaei headed Ansar Beit al-Maqdis, or the Champions of Jerusalem, a group that has claimed responsibility for most of the attacks on security forces and installations after Morsi's ouster. The military has responded with a sweeping crackdown.
There have been scores of attacks on the pipeline since the 2011 uprising that toppled Mubarak and the security vacuum that ensued.
In an election-related development, a European Union delegation said Friday that 150 of its observers will oversee the vote, both in Cairo and in the provinces.
The mission had initially announced it would only observe voting in Cairo after some of its equipment was impounded at the airport. After the equipment was returned, the EU said it would observe voting in the provinces as well.
The balloting will take place amid a widening crackdown on dissent in Egypt. On Friday, a prominent Egyptian columnist was barred from boarding an international flight at the Cairo airport, officials said.
Fahmi Huwaidi, a moderate Islamist who has written for the Qatari-based Arabic website Al-Jazeera and the Egyptian newspaper El-Shorouk, discovered he was on a no-fly list when he tried to board a plane bound for Spain.
Officials said he was allowed to return home without further incident.
Huwaidi has criticized Morsi's ouster and the ongoing crackdown on his Islamist supporters and the Muslim Brotherhood.
The Committee to Protect Journalists expressed "deep concern" about press freedoms in Egypt, where at least 16 journalists are detained and six have been killed since July.
Meanwhile, in Sinai, a police officer died from wounds sustained in a firefight with militants the previous night when his patrol came under attack near the border with Gaza, police officials said.
Two other policemen were wounded in the shooting, the officials said, speaking on condition of anonymity because they were not authorized to talk to the media.
Associated Press writer Laura Dean contributed to this report.