CAIRO, Jan. 25 (Xinhua) -- At least one people was injured on Saturday in a bomb attack near the Institute of Police Representatives in eastern Cairo on the third anniversary of an upheaval that toppled the 30-year ruler Hosni Mubarak, official news agency MENA reported.

　　An assailant riding a motorbike threw two small black bags at the building located in Ain Shams, a densely populated district, security sources said, adding that the explosion caused damage on the wall fence and wounded one person.

　　Meanwhile, unknown assailants from a car with no plates opened fire randomly at passers-by near Tahrir Square, the symbolic center of the 2011 mass protests, wounding three persons, the security forces then sealed off all the streets leading to the square, state-run Ahram website reported.

　　In the vicinity of the Interior Ministry, the armed forces also intensified the presence of its troops and sniffers dogs after a bomb planted near the General Intelligence headquarters was defused.

　　Elsewhere in Sinai peninsula, a stronghold of the hardline militants, masked gunmen attacked a gas pipeline in Bear Al Abed village, leaving one soldier dead. Several soldiers were wounded in another attack on a military checkpoint in Sheikh Zuweid city by rocket propelled grenades, a security source told Xinhua.

　　The attack came after four explosions targeting Egyptian police hit the country on Friday, which left six people dead and almost one hundred others wounded.

　　Meanwhile, at least 14 people were killed and 77 others injured on Friday during clashes nationwide between supporters of ousted Islamist president Mohamed Morsi and the security forces.

　　Ansar Beit al-Maqdis group, an al-Qaida-inspired Jihadist group based in Sinai, claimed responsibility for all the bombing attacks targeting in Cairo since Friday. It also warned the Egyptians from getting close to any police headquarters, vowing more attacks.

　　Since the removal of Morsi, tensions have been running high in Egypt with a string of bombings taking place across the nation, including a high-profile assassination attempt against the interior minister in last September.

　　Pro-Morsi supporters on Friday called for 18 days anti- government protests until Feb. 11, the day when Mubarak resigned.