CHICAGO — Pro-Palestinian demonstrators blocked roadways in Illinois, California, New York and the Pacific Northwest on Monday, temporarily shutting down travel into some of the nation's most heavily used airports, onto the Golden Gate and Brooklyn bridges and on a busy West Coast highway.

In Chicago, protesters linked arms and blocked lanes of Interstate 190 leading into O'Hare International Airport around 7 a.m. in a demonstration they said was part of a global "economic blockade to free Palestine," according to Rifqa Falaneh, one of the organizers.

Traffic in the San Francisco Bay Area was snarled for hours as demonstrators shut down all vehicle, pedestrian and bike traffic on the Golden Gate Bridge and chained themselves to 55-gallon drums filled with cement across Interstate 880 in Oakland. Protesters marching into Brooklyn blocked Manhattan-bound traffic on the Brooklyn Bridge. In Eugene, Oregon, protesters blocked Interstate 5, shutting down traffic on the major highway for about 45 minutes.

Protesters say they chose O'Hare in part because it is one of the largest airports. Among other things, they've called for an immediate cease-fire in the war between Israel and Hamas.

Anti- war protesters have demonstrated in Chicago near daily since Hamas' Oct. 7 attack on southern Israel that killed around 1,200 people. Israeli warplanes and ground troops have since conducted a scorched-earth campaign on the Gaza Strip.

The Israeli offensive has killed more than 33,700 Palestinians, according to the Gaza health ministry. The ministry does not differentiate between civilians and combatants in its count but says women and children make up two-thirds of the dead.

O'Hare warned travelers on the social platform X to take alternative forms of transportation with car travel "substantially delayed this morning due to protest activity."

Some travelers stuck in standstill traffic left their cars and walked the final leg to the airport along the freeway, trailing their luggage behind them.

Among them was Madeline Hannan from suburban Chicago. She was headed to O'Hare for a work trip to Florida when her and her husband's car ended up stalled for 20 minutes. She got out and "both ran and speed walked" more than a mile (1.6 kilometers). She said she made it to the gate on time, but barely.

"This was an inconvenience," she said in a telephone interview from Florida. "But in the grand scheme of things going on overseas, it's a minor inconvenience."

While individual travelers may have been affected, operations at the airport appeared near normal with delays of under 15 minutes, according to the Chicago Department of Aviation.

Inbound traffic toward O'Hare resumed around 9 a.m.

Near Seattle, the Washington State Department of Transportation said a demonstration closed the main road to Seattle-Tacoma International Airport. Social media posts showed people holding a banner and waving Palestinian flags while standing on the highway, which reopened about three hours later.

About 20 protesters were arrested at the Golden Gate Bridge demonstration and traffic resumed shortly after noon, according to the California Highway Patrol. The agency said officers were making arrests at two points on the interstate, including one spot where roughly 300 protesters refused orders to disperse,

"Attempting to block or shut down a freeway or state highway to protest is unlawful, dangerous, and prevents motorists from safely reaching their destinations," the agency said in a statement.

Oregon State Police said 52 protestors were were arrested for disorderly conduct following the Interstate 5 protest in Eugene, Oregon, about 110 miles (177 kilometers) south of Portland. Six vehicles were towed from the scene.

New York Police made numerous arrests, saying 150 protesters were initially involved in the march around 3:15 p.m., but that number quickly grew. The bridge was fully reopened by 5 p.m.

In Chicago, dozens of protesters were arrested, according to Falaneh. Chicago police said Monday that "multiple people" were taken into custody after a protest where people obstructed traffic, but they did not have a detailed count.