Turkish forensic police search a police bus after an explosion in Istanbul, on March 1, 2012.

Story highlights

NEW: 16 injured people are in "good" condition, police say

A plastic explosive mounted on a motorcycle explodes as a police van passes, officials say

Gov. Huseyin Avni Mutlu says authorities don't know who is responsible

Istanbul, Turkey CNN  — 

A bomb appearing to target police officers exploded Thursday in an Istanbul neighborhood near the ruling Justice and Development Party headquarters in the city, authorities said.

The blast left 15 officers and one civilian injured, Istanbul’s police chief, Huseyin Capkin, said. It occurred in the Sutluce neighborhood in Beyoglu district.

“It seems the explosion was done by remote control, as a police van with 21 policemen in it was passing by,” Capkin told reporters on the scene.

“Their conditions are all good,” Capkin said. “There is no one in a life-threatening condition.”

Istanbul Gov. Huseyin Avni Mutlu said the bomb was mounted on a motorcycle that was left by the side of the road. He said plastic explosive was used.

“We do not have clear information about the perpetrators,” he said, promising an investigation and vowing that such attacks could not harm Istanbul’s security.

The headquarters of Independent Industrialists’ and Businessmen’s Association, MUSIAD, is near the scene of the blast.

A spokesman for the association, Sadi Dinleyici, told CNN Turk television that the explosion shook their building and they were initially afraid it was hit by a bomb.

Turkey has experienced bomb attacks in the past conducted by various groups, including Kurdish separatist organizations, extreme leftists and al Qaeda-related radical Islamists.