Baltimore's race for mayor grew sharply negative Monday as state Sen. Catherine E. Pugh and former Mayor Sheila Dixon traded accusations of voter intimidation and illegal behavior. Each candidate asked state authorities to investigate the other's campaign.

Pugh and Dixon held dueling news conferences to criticize actions taken by one another's campaign workers and supporters during early voting.

Pugh — who held a slight lead over Dixon in the most recent poll conducted for The Baltimore Sun and the University of Baltimore — said Dixon workers and supporters have used cellphones to record people getting off Pugh's campaign buses at early voting sites, then shouted at them, “How much did you get paid to come and vote?”

“This is a shameful tactic and reminiscent of tactics the Republicans took in the 1980s to intimidate voters,” said Dara Lindenbaum, an attorney for Pugh's campaign. “The Democrats fought back then, and we are fighting back now.”

The Dixon campaign brushed off Pugh's allegations and focused on what the former mayor's campaign staff described as vote buying. The Baltimore Sun reported Saturday that as Pugh's campaign recruited potential primary election day workers Friday, it offered them free lunches and a ride to early-voting sites

The accusations came as more than 12,000 people across Baltimore turned out for the first four days of early voting in advance of the April 26 Democratic primary. Early voting ends Thursday.

The Pugh campaign called on State Prosecutor Emmet C. Davitt to examine whether the Dixon campaign attempted to suppress voters. Under Maryland election law, the use of “force, threat, menace, intimidation, bribery, reward or offer of reward” to influence voters is prohibited.

Martha McKenna, a spokeswoman for Dixon, said the Dixon campaign rejected accusations of voter intimidation. McKenna said the campaign will “continue to collect firsthand accounts from people who applied for jobs, as well as accept video evidence of the illegal vote-buying operation that the Pugh campaign is running.”

The Dixon campaign asked the state attorney general's office to investigate the Pugh campaign. The attorney general notified the prosecutor's office.

“We neither confirm nor deny investigations,” Davitt said Monday.

Two voters stood with the Dixon campaign on Monday to accuse Pugh of running what they said was a “scam.”

Raymond Fenwick Jr. and Rochelle Myers said they applied for jobs with the Pugh campaign but weren't paid. Instead, they said, they were pressured to vote that day for Pugh.

“They said, ‘You get paid $100 for working all day'?” on primary day, Fenwick said. “They fed us chicken. They gave us soda. They had music blasting. They said we had to go to early voting. On my bus, they said you had to vote for Pugh.”

Myers said she had responded to a flier offering $600 for a week of work.

“We thought it was six days,” she said. “They said, ‘We're only going to need y'all one day, the 26th. We're taking y'all to vote. You're on this bus to go vote.'?”

Myers said she didn't like the way she was treated and voted for Dixon.

Attorney Robert Fulton Dashiell, a Dixon supporter, called the Pugh campaign's tactics illegal.

“It's a very transparent and thinly veiled effort to buy votes,” Dashiell said. “There's a requirement that you get on a bus and go vote as a condition of getting a job for one day later on. There's nothing more desperate than buying votes, and that's what happened here.”

Pugh stood by her efforts to recruit job applicants and provide rides to the polls, saying that “we know the campaign laws.” Because those hired by the campaign will be busy on the primary election day, Pugh said, the campaign wanted to offer those potential workers rides to early voting. And those who rode the bus signed releases saying they boarded voluntarily, a campaign spokesman said.

Donald F. Norris, director of the School of Public Policy at the University of Maryland, Baltimore County, said the campaigns are looking for votes, and amplifying concerns about the opponent is part of that strategy.

“This is the final days of the campaign, and politics is a contact sport,” Norris said.

Pugh had the support of 31 percent of likely Democratic voters polled this month, while Dixon had 25 percent. They were followed by lawyer Elizabeth Embry at 9 percent and businessman David L. Warnock at 7 percent. City Councilmen Carl Stokes and Nick J. Mosby were tied at 5 percent. Mosby dropped out of the race last week.

Nina Kasniunas, an associate professor at Goucher College, said Pugh and Dixon are not the only candidates to have their campaign tactics called into question. Some voters told Kasniunas they didn't like Warnock supporters yelling through bullhorns at early-voting sites.

The accusations are common in Baltimore elections, Kasniunas said, pointing to similar complaints in 2011 by candidates running for various offices. State law prohibits campaigning within 100 feet of the entrance to a polling place.

Complaints filed with the state prosecutor likely won't be resolved before the primary, but Kasniunas said taking the action calls negative attention to opponents — though research shows that when candidates lob negative accusations at one another, voters become frustrated.

“This is a way to get attention that's not paid for,” Kasniunas said. “This is the dirty side of politics that nobody really loves, but this happens anyway.”

Embry said allegations of “corrupt behavior” have been a consistent theme during the election. She said both the Dixon and Pugh campaigns have been weighed down by the allegations.

“It is clear from the investigations and allegations of corruption, vote buying and voter intimidation being hurled by both the Dixon and Pugh campaigns that voters simply cannot trust either of them,” Embry said in a statement. “I will restore public trust to City Hall, not drag the city through endless investigations and scandals.”

Warnock said Pugh's and Dixon's actions are “exactly what's wrong with the leadership in Baltimore.”

“If they will do this to get elected, just imagine four more years of failed leadership,” he said in a statement. “Polls are open and voters must send a message with their vote if they want a new direction.”

Prominent Baltimore attorney William H. “Billy” Murphy Jr., who threw his support behind Pugh last week, said he believes voters are being intimidated by the Dixon campaign.

“This kind of stuff always happens at the last minute in campaigns,” Murphy said. “It's like finger-pointing, and most of it is absolutely frivolous.

“But we take very seriously the complaints that voters are being intimidated, because that is not the American way.”