Mohammed Yousri Yassin (search), 17, was extradited to Egypt on Saturday for his suspected connection to the April 7 homicide bombing in a Cairo bazaar that killed three tourists.
Yassin is also the younger brother of Ehab Yousri Yassin (search), who blew himself up with a nail-packed bomb on April 30 to avoid police capture near the Egyptian Museum, police said.
That blast was followed by a shooting in Cairo less than two hours later that reportedly involved the bomber's sister and fiancee, who police claimed later killed themselves. The two attacks wounded nine people, including four foreigners.
After the attacks, police began an intensive search for the younger Yassin. Police detained about 200 people from an area north of Cairo where the suspects once lived.
Egypt's intelligence service informed Libyan authorities of the younger Yassin's whereabouts in Libya after learning he crossed the border shortly after the attack, authorities said. Neighboring Egypt and Libya are bound by a pan-Arab treaty of security cooperation that permits extradition of terror suspects.
Libyan police found the younger Yassin hiding in a Libyan home rented by an Egyptian working as a hotel cook, said security officials who only discuss cases on condition of anonymity.
Two militant groups have claimed responsibility for the attacks — the Mujahedeen of Egypt and the Al Qaeda influenced Abdullah Azzam Brigades. Neither claim could be verified.