A 35-year-old low-ranking police officer, Mohamed Ahmed Nofal, died Saturday night from injuries sustained in a bomb blast near a police training centre in Egypt's Nile Delta city of Tanta, Al-Ahram Arabic news website reported.
The number of injured from the explosion, excluding the deceased policeman, stood at 16 as of Sunday morning, three of them civilians and 13 policemen, according to Al-Ahram Arabic news.
A Tanta health ministry official said four of the injured were still in a critical condition and undergoing surgery.
A military funeral for the policeman will be held later Sunday, according to authorities.
A statement from the interior ministry on Saturday said, "The bomb was planted in a motorcycle parked near the centre, and the area has been cordoned off and is being combed by security forces."
The militant group Lewaa Al-Thawra claimed responsibility for the attack in an online statement on Saturday, stating on Twitter that the bombing resulted in "dozens of deaths and injuries, and the safe withdrawal of our fighters after accomplishing the operation."
On Saturday night, Lewaa Al-Thawra posted a new statement on their Twitter account under the name of "traps for traitors", referring to 20 casualties, and claiming their attack as revenge of their "four martyrs" who were killed last month, and also for "the residents of Basarta in Damietta."
A heavy security crackdown has been in effect in Basrata village in the northern governorate of Damietta for the past few days. Officials were reported in local newspapers as saying that the crackdown was to arrest gunmen who killed a low-ranking policeman in the village.
Lewaa Al-Thawra also warned the police to "lay off, otherwise expect death, and explosives in every street," threatening death for what they described as "desperate regime criminals."
Lewaa Al-Thawra has claimed responsibility for several deadly attacks on security forces in recent months.
The group said it had murdered a high-ranking army officer in Dahshur, Giza, in October 2016. It also claimed responsibility for an attack on a security checkpoint in Menoufiya Governorate two months earlier in which two policemen were killed and five injured.
Egypt has been battling an entrenched Islamist insurgency in North Sinai for several years, with hundreds of security forces personnel killed in militant attacks.
Militants have also conducted deadly attacks against security personnel in Cairo and other governorates.