(CNN) -- Five people died when a car bomb exploded Monday in Cotabato City, in the southern Philippines, the state news agency reported.
At least 33 others were injured. The bomb went off during rush hour as a city administrator, attorney Cynthia Guiani-Sayadi, was passing through the area in a bulletproof vehicle, the Philippines News Agency said.
Guiani-Sayadi escaped unharmed, but one of her police escorts in a separate car was killed, the news agency said.
No one has claimed responsibility for the attack, it said. Officials are calling the act terrorism.
Guiani-Sayadi, sister of the local mayor, obviously was the target, Aniceto Rasalan, spokesman of Cotabato City Mayor Japal Guiani told PNA.
"We condemned this act of cowards," Rasalan said.
The blast came from a Toyota Town Ace passenger jeep in front of a funeral parlor, PNA reported. Other vehicles parked nearby were burned and the impact sent passing motorcycles flying.
The blast site is on a busy street near a medical center, a convention center, and the seat of the Autonomous Region in Muslim Mindanao.
Guiani-Sayadi had been traveling to evacuation centers for residents displaced by floods.