Two bombs exploded in a Cairo suburb Saturday, killing a teenager and wounding her mother.
Security officials said the homemade bombs hit a telecommunications building that was still under construction in the 6 October district. The victims were the wife and daughter of the building's security guard.
Local officials said they are working to restore telephone service to some 800 people whose lines were affected by the blast.
The double bombing is the latest in a string of blasts to hit in and around the Egyptian capital. Saturday's blast comes after at least four makeshift bombs exploded in Cairo earlier this week.
Militants have carried out a series of bombings and shootings since the army ousted Islamist president Mohamed Morsi last July. Most of the attacks have taken place in the restive Sinai Peninsula, but have spread to other cities, including Cairo.
Earlier this month, the government said such attacks have killed nearly 500 people, most of them soldiers and police.