The Harvard University Police Department (HUPD) sealed off a Winthrop House courtyard for decontamination last Friday morning after discovering a suspicious white powder on the ground. The powder was taken to the Massachusetts State Laboratory for anthrax testing.

Authorities expect test results by the end of this week, according to HUPD spokesperson Steven G. Catalano.

The suspicious powder was found on the sidewalk inside the main gate of the courtyard leading to Winthrop’s D and G entryways.

HUPD was contacted about the powder sometime around 9 a.m. and called the hazardous materials (HAZMAT) team soon after.

While the HAZMAT team dealt with cleaning the area, HUPD officers sealed off both the courtyard’s main gate and the doors leading to the D and G entryways that open onto the courtyard.

The police lines were removed around 10 a.m.

Yuval H. Grill ’03, who lives in Winthrop’s D entryway, said he was startled to see a HAZMAT truck as he awoke for class in the morning, but added that he is not overly concerned about the anthrax threat.

“There was about a square foot of powder, and it just looked like some chalk or detergent,” Grill said.

National fears of terrorist attacks involving anthrax have echoed within the Harvard community in the last few weeks, with HUPD receiving multiple daily phone calls about mysterious letters and powders.

Between Sunday and Saturday of last week, for example, there were at least 26 HUPD dispatches over anthrax concerns.

So far, however, no trace of anthrax has been identified at Harvard.

—Staff writer Alex B. Ginsberg can be reached at ginsberg@fas.harvard.edu.