The explosion in the Cathedral Quarter of Belfast occurred as officers were clearing the area after receiving a telephoned bomb warning, UTV has reported.
The warning was phoned into the Irish News at around 6pm before the bomb partially exploded just before 7pm in the Exchange Street West area.
More top news
This is what we know so far about the young boy who was found washed up on Bodrum beach in Turkey.
Weather set to stay cool and cloudy tomorrow
Europe's asylum, immigration and freedom of movement laws "wholly inadequate" to deal with arrival of hundreds of thousands of people.