Seeking to end more than two weeks of a precipitous drop in police activity, Police Commissioner William J. Bratton said on Friday that he had instructed top commanders to do what they could to reverse the trend.

The message, which was delivered to union leaders on Wednesday and to commanders over the next two days, was relayed to rank-and-file officers during roll calls on Friday, according to people familiar with the discussions; one supervisor said that officers were told to “start working again.”

It appeared that the message had gotten through.

“The slowdown is over in the sense that the numbers are starting to go back up again,” Mr. Bratton told reporters on Friday. “I anticipate by early next week that the numbers will return to their normalcy.”

Mr. Bratton said he would not release the precise number of arrests and summonses until Monday.

In the courts on Friday, the number of people being arraigned on criminal charges had doubled compared with earlier in the week, but had still not reached normal levels. As courts opened, 479 people arrested on Jan. 8 were waiting to see a judge, compared with 212 arraigned citywide on Jan. 2.