KABUL, Afghanistan — A bomb-laden vehicle detonated in a large explosion heard across Kabul late on Monday, and officials said the blast killed at least four people and wounded 90.

The vehicle blew up in the eastern part of the Afghan capital, home to government offices, the country’s elections commission, housing for foreign security contractors and agencies of the large United Nations mission.

The exact target was not clear. Witnesses and officials suggested the vehicle had detonated at a roundabout, an indication the blast occurred before the actual target had been reached.