Tucson police said 13 people protesting the state's new immigration law were arrested for blocking downtown streets Thursday afternoon.
West Congress Street and Granada Avenue were closed for more than an hour because of the protests. Police arrested and cited the 13 while others were told to move out of the roadway.
Twelve of the protesters were cited for failing to disperse following police commands. One protester was cited for threats and intimidation.
All were cited and released, police said.
Earlier Thursday, traffic on Interstate 19 was briefly disrupted south of Ajo Way after a group of protesters placed tar and tires on the highway.
A group calling itself "Freedom for Arizona" said it planned to cover the southbound lanes of I-19 with tires covered in tar and broken glass to shut down "the very road that is used to deport people deemed 'illegal' as well as a direct disruption of the flow of capital," the group said in a news release.
Law enforcement officials have cleaned up the tires and reopened the interstate, according to the Department of Public Safety.
There were no reports of injuries.
Andres Chavez was arriving home from school and saw the whole incident. He said two trucks driving parallel on southbound Intestate-19 between Ajo and Valencia stopped and threw tires connected by rope from the truck beds.
The 8-12 men in the trucks then threw brown paint, broken glass and a sign over the tires. The sign read: "Stop the militirazation on the border." Then, they drove away, Chavez said.
"They halted traffic completely and almost got rear-ended by cars behind them," Chavez said.
Chavez pulled the 15-20 tires off the road because he was worried about wrecks.
"I have no problem with people protesting or whatever, but they were putting people's lives at risk," said Chavez, a 23-year-old University of Arizona journalism student. "There could have been a multi-car pile up there."
He described the tire-throwers as men between the ages of 20-25 who wore regular regular clothes.
In its news release, a group claiming responsibility said: "Neither SB 1070 nor the deployment of National Guard troops to the border do anything to address the root causes as to why people migrate.
"U.S. economic policies and wars have displaced and impoverished millions of people all over the world. Capital-driven policies, such as NAFTA, create poverty. These policies and laws not only consume and exploit land and people, but they also displace us from our homes, forcing us to migrate in order to survive."
Meanwhile in downtown Tucson there were mostly peaceful protests in front of the state building at Congress and Granada.
One man, who supported SB1070, was arrested on suspicion of the threats and intimidation after he continued agitating those opposed to the law, and threatening two people, said Sgt. Fabian Pacheco, a Tucson Police Department spokesman.
Officers had asked him to calm down before the arrest. He was removed from the protest area and taken to the Tucson police west side substation. The man was cited and released.
That was the only arrest at the Tucson events.
Several hundred people with signs, bull horns and drums demonstrated Thursday morning, most of whom oppose the law. Most said they were pleased with the ruling from U.S. District Court Judge Susan Bolton that blocked key provisions in the law but that they still had concerns about the remaining provisions that went into effect.
"I'm pleased but not satisfied," said Lino Vasquez, a 25-year-old college student.
"It was a small stepping stone," said Angelina Castrillo-Sereno, who brought her two children with her to the rally.
There was also supporters of SB1070 who were unhappy with the judge's decision.
"I'm very disappointed," said Renee Allison, of Tucson. "It's a very sad day. It's sad that people don't support the law."
By 11 a.m., the number of protesters had decreased substantially.
Opponents of Arizona's immigration crackdown went ahead with protests Thursday in Phoenix despite a judge's ruling that delayed enforcement of most the law, and dozens of people in Phoenix were arrested after peacefully confronting officers in riot gear.
Outside the state Capitol, hundreds of protesters began marching at dawn, gathering in front of the federal courthouse where Bolton issued her ruling on Wednesday. They marched on to the office of Maricopa County Sheriff Joe Arpaio, who has made a crackdown on illegal immigration one of his signature issues.
At least eight protesters approached a police line and allowed themselves to be arrested. A group of about two dozen protesters then sat down in the middle of the street or refused to leave, and police arrested them as well.
Earlier, three people were detained at the courthouse after apparently entering a closed-off area. Former state Sen. Alfredo Gutierrez, who ran unsuccessfully for governor in 2002, was among them.
Marchers chanted "Sheriff Joe, we are here, we will not live in fear," and among the crowd was a drummer wearing a papier-mache Sheriff Joe head and dressed in prison garb.
The Associated Press contributed to this story