A man drove up to a White House checkpoint this weekend claiming to have a bomb in his car ... marking the 3rd time in a week someone has tried breaching the grounds.
The Secret Service arrested the latest would-be intruder late Saturday night.
He was immediately taken into custody, and the White House was put on high alert. Surrounding streets were closed through the night. His vehicle was searched ... there is no confirmation if anything was found.
President Trump was not home at the time -- he's in Mar-a-Lago this weekend.
Earlier the same day, another man tried jumping over a bike rack in front of the White House. Last Saturday, a man actually jumped the White House fence and remained undetected for about 20 minutes ... getting right up to the building and even trying to jiggle doorknobs.
We broke the story ... last week's intruder had been turned away by Secret Service hours earlier. Yet, agents did not have eyes on him when he made his move.