Hamas has denied involvement in Tuesday's terrorist attack in Mansoura that killed 15 and injured 134.
We have no link to this attack or any other attack in Egypt and we condemn such accusations, the Palestinian Islamist movement's spokesperson Sami Abu Zuhri said in a statement.
Fifteen people died and 134 were injured on Tuesday morning when a large bomb struck the Nile Delta city's security directorate. Widespread damage was caused to buildings in the vicinity, including the city's council building, a state-owned theatre and a bank.
Initial findings indicate a suicide car bomb caused the blast, the interior ministry said.
Attacks on security targets, mostly in the Sinai Peninsula, have been on the rise since Mohamed Morsi's ouster. There have been sporadic attacks in the capital and other provinces.
Al-Qaeda-inspired Islamist militant group Ansar Beit Al-Maqdis has claimed responsibility for a number of recent attacks in Egypt, including a failed assassination attempt on the interior minister in September.
On Monday, the group threatened an escalation of violence, according a statement published on Islamist militant websites.
Militants in Sinai are believed to have links with extremist groups across the border in Gaza. Mohamed Morsi, among other charges, is to stand trial for conspiring with Hamas and other militant groups to destabilise Egypt.