The quake had a magnitude of 6.1, the US Geological Survey said, and was very shallow at a depth of 6.2 miles (10 km). It was previously reported as having various magnitudes ranging up to 6.4.
Some residents in Managua rushed out into the streets, clearly nervous.
"There are no injuries, no loss of life so far, nor even any significant material losses," Nicaraguan government spokeswoman Rosario Murillo said on local radio, adding that the government was checking reports that two dozen homes had suffered some damage.
The earthquake struck at 2327 GMT, 19 miles (31 km) northeast of the town of Nagarote or 31 miles (50 km) north-northwest of the capital Managua, USGS added.
The Reuters witness said the quake was followed by aftershocks.
A magnitude 6.1 quake is capable of causing severe damage