More than 70 people were arrested Wednesday during a chaotic and often tense day of protests in downtown Washington as members of the Occupy movement blocked intersections and snarled traffic along K Street for hours.

Hundreds of protesters from Occupy D.C. and around the country joined in the “Day of Action: Occupiers Unite,” targeting K Street NW — the symbolic hub of the country’s lobbying industry.

As a cold rain fell, hundreds of people filled K Street chanting “We are the 99 percent” while slogging through puddles and waving protest signs. They blocked intersections with newspaper boxes, wooden pallets, office furniture and tents. Tempers frayed. Horns blared.

D.C. police said 62 people were arrested after they formed human chains across thoroughfares. Many were charged with obstruction of a public highway. On Wednesday night, 12 more people were arrested when they wouldn’t leave the steps of the Supreme Court.

Protesters said they were trying to call attention to what they see as the corrupting nexus of politics and money in the nation’s capital.

In the daylight, they marched and chanted in front of a high-profile lobbying firm co-founded by a former chief of staff in the Clinton administration. Other protesters swarmed Capitol Hill this week to demand jobs and economic equity, staged sit-ins at congressional offices, protested fundraisers and chanted in front of Charlie Palmer Steak, a favorite restaurant of the D.C. elite, where a steak-and-lobster combo is $64.

“K Street is the place to be if you’re going to stop the moneybags who are corrupting our government,” said Jim Sessions, 75, a Methodist minister from Tennessee who was arrested Wednesday. He and eight others from Texas, Massachusetts and Washington state had linked arms across K and 16th streets and refused to move.

Dozens of others were dragged by police off the street, where they lay side by side, linking arms in the heavy rain.

“Getting arrested will make people think: ‘These people care enough to be arrested? This must matter,’ ” said Natalie Atwater, 20, of Austin.

The ranks of the Occupy demonstrators swelled this week because of a similar protest called “Take Back the Capitol,” prompting hundreds of demonstrators from around the country to park themselves on the Mall. This group, responsible for many of the disruptions at the Capitol, is backed by the powerful Service Employees International Union and the progressive activist group

This week marked the first large-scale escalation of tension between the Occupy D.C. protesters and police at the encampment at McPherson Square, where dozens have been living since early October. On Sunday, 31 protesters were arrested in a day-long standoff with U.S. Park Police after they began erecting a wooden structure in the park that they hoped would be their winter headquarters. The structure has been taken down.

On Monday, a U.S. District judge ruled that the National Park Service must give protesters some notice if it moves to evict them, except in emergency situations. A protester had sought the ruling to clarify the rights of protesters, who have been living in McPherson Square without a permit since Oct. 1.

As Wednesday’s chaos disrupted traffic and delayed bus service, commuters and others began to show frustration with the Occupiers — although some still said they agree with their message.

Jonathan Agin, 40, of Arlington County was furious as he sat at a bus stop at 14th and K streets.

“This is not the way to get out your message,” he said. “They are tying up traffic of people who need to get somewhere. . . . Police need to get them out of here. . . . These people, they have no idea who is in these cars and where they need to be and what hardships they may be causing them.”

Staff writers Mark Berman, Mary Pat Flaherty, Teresa Tomassoni, Robert Samuels and Clarence Williams contributed to this report.