More Americans signed up for health insurance through the federal online exchange on the first two days of December than in all of October, a source familiar with the enrollment numbers tells ABC News.

Roughly 29,000 people completed applications and selected a plan through the revamped HealthCare.gov site between midnight Sunday and midnight Tuesday, the source said. It is not clear how many of those paid their first month's premium, which is how insurers formally define enrollment.

In October, 26,000 people selected plans through the federal system, according to the Department of Health and Human Services.

The latest figures are a burst of good news for the Obama administration following the relaunch of its signature insurance website. Traffic to the site continues to be high, topping 1 million visitors on Monday and 950,000 visitors on Tuesday, officials said. The White House says the volume reflects serious, persistent interest in signing up.

Approximately 100,000 Americans selected plans through the federal exchange in November, a significant increase in sign-ups but still lagging behind pace for a White House target of 7 million by March 31. More comprehensive figures for last month, including state by state data and other metrics, will be released in the next two weeks, an administration official said.

The early December enrollment figures were first reported by Politico.