Destroy incoming blast bots is a mission in Jak 3. The KG Death Bots launched an assault on the Port using blast bots, Torn asked Jak to take him out and aid the Freedom League. The mission is similar to the mission "Protect hideout from bombots" in Jak II.
The PlayStation 3 and Vita versions of this mission are related to a trophy named "Boom Bada Boom", completing this mission will reward you with a bronze trophy.
The blast bot's main weapon is the large auto-aiming turret on top of it, which can take down zoomers and various enemies down at a long range with ease. Nonetheless you will want to get in close using a zoomer as the Port district is too large to cross with the JET-Board or on foot. Once you have closed the distance, leave the zoomer and start attacking it as close as possible to its main body. The Arc Wielder with the robot shock upgrade is the best weapon here, but otherwise the Beam Reflexor works too (plus it takes out other enemies around you).
In Jak 3 they have a new attack where they stop moving around and launch a couple of small bombs at your direction. They will explode quickly, so kick them back to deal some extra damage, similarly to the Widow mech bossfight in Jak II. Once enough damage has been dealt it will start beeping rapidly and collapse on its legs, make sure to get out of the way as it will explode shortly afterwards.
If you fail you stop a blast bot and allow it to get close enough to the Naughty Ottsel a timer will appear, leaving you with ten seconds to finish off the blast bot before it explodes and ends the mission.