Two men were shot Monday afternoon in the midst of a knot of people on Connecticut Avenue NW near the National Zoo, site of an annual Easter event that drew thousands of people over the course of the day.

Neither man was thought to be seriously wounded. One was struck in the hand and found in the 3000 block of Connecticut, just outside the zoo. The other was found about four blocks away.

No motive was known in the shootings, D.C. police said. Cmdr. Michael Reese, head of the 2nd Police District, said investigators thought that just before the shooting a group of 30 to 50 people had been walking on Connecticut.

About 5:15 p.m., according to police accounts, gunfire broke out within the group. It was not clear who fired. Gunshots in that Northwest Washington neighborhood are unusual.

Police had no information on what had led to the shooting, ­Reese said, and authorities are hoping to hear from witnesses.

According to at least one news media account, the man struck in the hand may have wounded himself by accident. However, Assistant Police Chief Peter Newsham said authorities did not know whether that had happened. He said police had “nothing to confirm or disprove it.”

The gunfire broke out on a bright, warm day despite a heavy police presence near the zoo, which was hosting annual Easter Monday activities, a Washington tradition more than 100 years old. Visitor traffic at the event usually clogs Connecticut close to the zoo.

The event has been followed by violence at or near the zoo on at least two previous occasions. In 2000, seven people were shot at an entrance to the zoo. Three years ago, a teenager was stabbed in a fight at the zoo.

Zoo spokeswoman Devin Murphy said she knew of nothing suggesting that Monday’s gunfire was related to anything that had occurred at the zoo. About 16,000 visitors had been counted by late afternoon, but it was not known whether any of those involved in the violence had been among them, Murphy said. She said the Easter Monday events had ended about 4 p.m.

Bri’Ana Jenkins and her friend, Par’Ris Thompson, both 19, said they were at the zoo entrance and preparing to head inside late in the day. The women said they were lingering near the entrance, hoping they could get inside, when they heard two shots.

Dozens of people, some with strollers, poured back into the zoo to search for cover, the women said. They saw some people hiding behind trees.

When shots rang out, people who had left the zoo “bombarded back inside,” Thompson said.

“Back in the zoo. That was the safest place to be,” Jenkins said.

The women said it appeared that the shooting occurred across the street from the zoo entrance, near a Starbucks and a hot-dog vendor.

One Starbucks employee said she heard one or two gunshots right outside the building. A man standing next to the hot-dog stand in front of Starbucks said the shooting occurred there.

Murphy, the zoo spokeswoman, said that after the gunfire, zoo gates were closed to new arrivals but that those already inside were permitted to stay.

It was determined by 6 p.m. that zoo visitors were safe to leave. The zoo normally closes at 6 in April.

At one point Monday afternoon, police said they were looking for two male teens who may have been involved in the incident. Later they said they had no description of a suspect.

Effects of Monday’s incident rippled up and down the avenue.

The Cleveland Park branch of the D.C. Public Library remained closed hours after the shooting. “The library is under lockdown until further notice,” signs read.

Groups of yoga students hoping to use the library’s community room and parents with children waited outside wondering whether the library, three blocks north of the zoo, would reopen before its regularly scheduled 9 p.m. close. Restaurants near the library were teeming with people seated outdoors to enjoy the mild evening.

Shortly after 7 p.m., friendly librarians reopened the building “to anyone who doesn’t look dangerous,” one staffer joked. Everyone waiting got in.

Marc Fisher and Ian Shapira contributed to this report.