BATON ROUGE, Louisiana (AP) -- Officers in riot gear arrest dozens in Louisiana's capital near the close of a long hot weekend of protests over the killings of black people by police, with demonstrations around the country punctuated by activist attempts to block some key interstates.
Helmeted police moved in and kept a group of protesters late Sunday in Baton Rouge from entering a major artery, Interstate 110 in Baton Rouge, thwarting a tactic that social justice activists have increasingly tried in some major cities to protest the deaths.
Authorities reported one officer injured when he was hit by a projectile in Sunday's protest.
Tensions between black citizens and police have risen palpably since last week's killings of Alton Sterling in the Louisiana capital, Baton Rouge, and Philando Castile in Minnesota by white officers, and a retaliatory attack on white police by a black sniper in Dallas that killed five officers and wounded several others including two civilians.
More than a thousand people left a Black Lives Matter rally in Memphis, Tennessee, and occupied a key bridge over the Mississippi River on Sunday night, temporarily blocking all traffic on Interstate 40.
On the West Coast, hundreds of people poured into the streets of in Southern California late Sunday night, shutting down a major intersection and blocking traffic on the 405 Freeway for several minutes while peacefully protesting the recent fatal police shootings of black men. Authorities told the Los Angeles Times there were no arrests and no reports of violence.
Several hundred people blocked an area of Interstate 94 in Minneapolis-St. Paul on Saturday. And hundreds answered a call by that group to march onto I-264 in Portsmouth, Virginia, marooning motorists for hours inside the area's Downtown Tunnel recently. In recent days, demonstrators also tried but failed to block highways in Atlanta and Columbia, South Carolina, while in San Francisco, police managed to keep them off the Bay Bridge.
Leaders in some local communities have sought to discourage the traffic-blocking tactics.
"While I appreciate the peaceful intent of this weekend's rallies, I'd ask that we not put our fellow citizens or law enforcement at risk — which is exactly what attempting to block highways does," South Carolina Gov. Nikki Haley said in a statement.
In Louisiana, some 2,000 people rallied peacefully Sunday outside the Capitol building, State Police Maj. Doug Cain said.
"They didn't have any problems out there. They seemed to be very organized and peaceful," Cain said.
By Sunday night, a few hundred people aimed for an on-ramp of Interstate 110 in Baton Rouge.
After a lengthy standoff, more police in full riot gear moved in, pinning some of the protesters as others fled. Some 30 to 40 people were taken into custody for trying to block a highway, sheriff's spokeswoman Casey Rayborn Hicks said.
Video footage showed helmeted officers reaching into a crowd of chanting demonstrators and seizing individuals. The arrests brought the count to more than 160 taken into custody in recent days in the Louisiana capital.
Louisiana Gov. John Bel Edwards said at a late weekend news conference that he was "very proud" of the his state's law enforcement response. Flanked by officers in uniform, Edwards said he didn't believe using riot gear to push protesters away from highway ramps was overly aggressive.
"I can assure everyone we are hearing the protesters," the governor added at the news conference. "We are listening to their voices. But I'm especially gratified that our citizens here in Louisiana, to a very large degree, have decided to protest in a constructive and peaceful manner."
A Baton Rouge police spokesman, Sgt. Don Coppola, had blamed the large number of arrests on outside agitators. Police also confiscated three rifles, three shotguns and two pistols during that protest, he wrote in an email.
But most of those detained live in Louisiana — the Baton Rouge and New Orleans areas mostly — and faced a single charge of obstructing a highway, the sheriff's spokeswoman Hicks said.
Some of the recent demonstrations in Baton Rouge began at the convenience store where 37-year-old Alton Sterling was killed while two police subdued him. The U.S. Justice Department has launched a civil rights investigation.