CHICAGO — A few dozen protesters chanting “Free, free Palestine!” gathered Tuesday outside a skyscraper that houses the Israeli consulate for a pro-Palestinian demonstration on the second night of the Democratic National Convention. Some carried Palestinian flags, while many others wore black and covered their faces.

Dozens of Chicago police officers were posted outside the building, where law enforcement had closed down most of the entrances to the building on Tuesday, allowing commuters to come in only one entrance where armed officers were also posted. Many of the building’s shops were closed. Martha Hill, a spokeswoman for the Metra commuter rail service, says train service is running as normal.

Meanwhile, the sites of demonstrations from the previous night were largely quiet. Thirteen people were arrested during Monday’s protests, most them related to a “brief breach” of security fencing “within sight and sound of the United Center,” the city’s police superintendent said.

In downtown Chicago, security was tighter than usual — including law enforcement officers with weapons slung across their bodies — outside the office building that houses the Israeli Consulate and a major city transportation hub. Metal barricades were set up, and an officer said they were preparing for a 7 p.m. demonstration.

The consulate, located about 2 miles (3.2 kilometers) from the United Center, has been the site of numerous demonstrations since the war in Gaza began in October. It is in a building connected to the Ogilvie Transportation Center, a major commuter rail station.

Israel supporters, including some relatives of people kidnapped by Hamas, gathered earlier in the day at a pro-Israel art installation not far from the consulate to call on U.S. leaders to continue backing Israel and pushing for the release of hostages. The art installation included giant milk cartons bearing photos of some of the hostages.

Elan Carr, CEO of the Israeli-American Council, condemned the pro-Palestinian protesters who have descended on Chicago this week, calling them “fringe crazies” and demanding that U.S. leaders “stand unequivocally with the state of Israel.”

More protests were planned throughout the week. However, attendance at the main rally on Monday was far below estimates of organizers who had predicted more than 20,000 would show up.

Chicago Police Superintendent Larry Snelling said Tuesday that the crowd was around 3,500 strong and that the vast majority of the protesters were peaceful.

However, some clashed with police, used pepper spray against them and threw water bottles at officers during the clash in the park where there was a breach in security fencing, Snelling said. He said officers did not use any chemical sprays.

“Our officers showed great restraint,” he said at a news conference. “We’re not going to tolerate vandalism and violence in our city. … We’re going to continue to protect the city.”

Snelling said with more protests planned, his department is prepared to de-escalate situations whenever possible.

“Again, we’re up to the challenge,” Snelling said. “The city is up to the challenge.”

The park where the most arrests were made, located a block from the convention arena, served as a destination point for a march of thousands calling for a cease-fire in the Israel-Hamas war. Several dozen activists broke off from the main group, breached the fencing, and were pushed back by police.

Authorities said the inner security perimeter surrounding the United Center was not breached and there was no threat to those attending the convention.