SAO PAULO — The editor-in-chief of a newspaper that crusaded against corruption in Brazil's rough border region with Paraguay was shot dead, police said Monday, just days after another slain journalist's body was found in a different state.

Paulo Rodrigues, 51, was approached by two men on a motorcycle while driving late Sunday through the town of Ponta Pora in Mato Grosso do Sul state, where his Jornal da Praca newspaper and website are based, police said.

The gunmen fired 12 shots, five of which hit Rodrigues. He died in a hospital hours later.

Rodrigues' killing comes after the shooting death last Thursday in Rio de Janeiro state of Mario Lopes, who wrote against corruption on his website Vassouras na Net. Police said Lopes already survived one attempt on his life last year, when he was hit by five shots while inside his office. He continued writing.

The deaths come at a time when journalism is under threat in Brazil, according to watchdog groups.

Reporters Without Borders said in a January report that Brazil plummeted to 99th place last year on its ranking of freedom of the press in nations around the globe. That was a drop of 41 places from the year before, a tumble attributed to violence against journalists.

The New York-based Committee to Protect Journalists said six Brazilian journalists were killed in 2011.

Leo Veras, a photo journalist who worked alongside Rodrigues, said that despite his scathing articles on corruption, his shooting remains a mystery.

"He was a critic, but he was beloved. We don't understand this cowardly crime at all," Veras said by telephone. "The newspaper defends the poor in our city and Paulo criticized corruption, but he was respected by leaders."

Veras and other another journalist who worked with Rodrigues said they didn't know of any investigative story that would have prompted his killing, despite the region being known for drug and gun trafficking, in addition to political corruption.

"I don't think a drug trafficker is responsible for this — they don't really have the power nor would they want the attention. Whoever did this is either an idiot or is new to the area and trying to show off some power," he said.

Flavio Kayatt, the mayor of Ponta Pora where Rodrigues died and who in 2009 threatened to sue his newspaper for what he said were misleading articles on municipal corruption, said he considered Rodrigues one of the best journalists of the region.

"He was extremely competent and idealistic. We had to respect his opinions," Kayatt told the Campo Grande News in the state capital. "Of course, he had ideologies that didn't meet ours, but we had a good relationship."

The photo journalist Veras verified that Rodrigues and Kayatt were friendly and often met to discuss various issues facing the city.

"We've been sharply criticizing the mayor for eight years and have never been threatened," Veras said. "We're bewildered by this crime."

Associated Press writer Marco Sibaja contributed to this report from Brasilia.