MADISON, Wisconsin (Reuters) – Dozens of protesters against proposed legislation to weaken state public unions refused to leave the Wisconsin state capitol building on Sunday and police said they would be allowed to stay the night.

Hundreds had remained in the Capitol from a massive protest rally on Saturday, with hundreds more outside in chill winter weather. Police had announced they would close the building at 4 p.m. for cleaning and custodial work.

Many filed out of the capitol building as ordered. But about 200 refused to leave, with many mingling with assembled local police and building workers. Floor polishing and other work started and protesters did not interfere.

"They are allowed to stay tonight, but we are going to go back tonight and evaluate our procedures," Charles Tubbs, head of Capitol Police, told reporters.

He said there had been no arrests for violations and the Capitol building would open again for normal business hours on Monday at 8 a.m. after maintenance with stricter rules.

"Mattresses and all the other items, they will not be allowed in here tomorrow," Tubbs said.

He said the decision to allow protesters to stay was made based on the cooperation he'd seen and the fact that "we had a large number of people who were not planning on leaving."

"We have asked and the citizens have cooperated," he said.

Protesters, some who have camped in the building since February 15, greeted the news happily, with some dancing under the rotunda.

Earlier, demonstrators outside the Capitol greeted those exiting with chants and support on Sunday afternoon.

"Let us in!" chanted the crowd. "We are Wisconsin, the whole world is watching!"

"It's cold outside, not as cold as Gov. Walker," read one sign held by a protester.

A crowd estimated at more than 70,000 people on Saturday waved American flags, sang the national anthem and called for defeat of a plan by newly elected Republican governor Scott Walker to curb public sector union collective bargaining that has galvanized opposition from the American labor movement.

Wisconsin's state Assembly approved Walker's plan early on Friday morning but Senate Democrats have fled the state to prevent a vote in that chamber, which also must pass the bill.

Walker says the plan is vital to close a budget deficit of $137 million for this fiscal year.

On Sunday, Walker said he would not back down in his confrontation with the public sector unions and repeated his threat to lay off state workers if the standoff continues.

"If we do not get these changes and the Senate Democrats do not come back, we're going to be forced to make up the savings in layoffs and that to me is unacceptable," Walker said on NBC's "Meet the Press."

Protesters on Sunday rejected Walker's arguments.

"It's not about the budget," said one protester, Kevin Logan, a 36-year-old union worker from Illinois. "Everybody's made concessions. They meet what they need as far as the budget goes. It's just a ploy to bust unions, that's all it is."

Crowds thinned around the capitol after exit doors were locked. But one group continuing their calls, "The people united will never be divided."

Car horns blared in support as vehicles drove past. One demonstrator said they, as a group, will continue their actions until tomorrow. Others mentioned coming back tomorrow.

The rotunda remained full, with protesters banging drums amid chants of "Tell me what democracy looks like." Outside, a man with an accordion was laying polkas and people waiting to enter the building were chanting "Whose house?" "Our house!"

The options on the leaflets include leave peacefully, allow themselves to be escorted out, or go limp and be carried out. But police and demonstrators reported no incidents.

Hattie Chamberlin, 18, a college student from nearby Sauk Prairie who wants to be a teacher, said the people did not want to give police, a public union themselves, a hard time.

"We don't want to put them in a position where they are struggling to decide what to do," Chamberlin said. "They're fighting the same fight we are."

(Writing by David Bailey; Editing by Peter Bohan)

WASHINGTON (Reuters) – Frank Buckles, believed to be the last surviving U.S. veteran of World War One, has died at age 110, according to media reports Monday.

The Washington Post, quoting his daughter, said Buckles died Sunday at his farm in West Virginia.

Buckles, who celebrated his 110th birthday on February 1, lied about his age to join the army at age 16. The Missouri native was among nearly 5 million Americans who served in World War One in 1917 and 1918.

"I knew there'd be only one (survivor) someday. I didn't think it would be me," he was quoted as saying in recent years.

Buckles drove an ambulance during the war. In 1941, while working as a civilian in Manila, he was captured by the invading Japanese and held prisoner for 38 months during World War Two.

The Post said that with Buckles' death, only a 109-year-old Australian man and a 110-year-old British woman were believed to survive from the estimated 65 million people who served in the 1914-1918 war.

(Writing by Peter Cooney; editing by Tim Pearce)

MEXICO CITY (Reuters) – The Mexican Navy said on Sunday it arrested the alleged regional head of the feared "Zetas" drug gang in connection with this month's murder of a U.S. customs agent by a drug gang.

The Navy said in a statement that Marines arrested Sergio "El Toto" Mora, the alleged head of the Zetas in San Luis Potosi, in a Sunday morning raid in the northern city of Saltillo.

Mora was to be transported to Mexico City and handed over to the federal prosecutors' office for interrogation.

The statement did not provide further details of Mora's suspected role in the killing.

A news conference where Mora was to be presented to journalists in Mexico City was canceled shortly before it was supposed to begin Sunday evening.

U.S. Immigration and Customs Enforcement (ICE) agent Jaime Zapata died and his partner was wounded when they were ambushed in broad daylight on a major highway outside of the city of San Luis Potosi earlier this month by alleged drug gang members.

It was one of the worst attacks on U.S. law enforcement personnel in Mexico in more than a decade.

Mexico's federal prosecutors' office believes the attack was due to a mistaken identity, but it has come under heavy diplomatic pressure from Washington to capture Zapata's killers.

Security forces have already arrested six men, four women and a minor in connection with the attack, all of whom are allegedly linked to the Zetas.

Nine of those arrested were ordered held in prison for 40 days on Sunday by a Mexican judge to allow prosecutors more time to collect evidence against the suspects before they were charged.

The Zetas, formed by renegade Mexican special forces soldiers who deserted to become the armed wing of the Gulf Cartel, have grown in power. They turned on their former masters last year to battle for control of lucrative drug smuggling routes in northern Mexico.

Escalating drug violence in Mexico, a top U.S. trade partner, has caused alarm in Washington, which is providing $1.3 billion in funding and training to help battle the local cartels.

Mexican President Felipe Calderon has made crushing the cartels a top priority of his government and has sought to enhance cooperation with U.S. authorities in his fight.

More than 34,000 deaths are blamed on drug violence since Calderon took office in late 2006 and launched his army led campaign against the gangs.

(Reporting by Robert Campbell; Editing by Cynthia Osterman and Paul Simao)