MEXICO CITY -- A journalist was shot dead in the southern state of Oaxaca on Thursday, the fifth killed this year in Mexico, the state prosecutor's office said in a statement.

An official with the Oaxaca state security agency, who requested anonymity, confirmed that the victim was Heber Lopez, director of the online news site Noticias Web.

The Oaxaca state prosecutor's office said that two suspects in the killing were in custody and a gun had been recovered from them.

Rodolfo Canseco Gutierrez, director of the online news site RCP Noticias and a longtime friend of Lopez's, said the journalist covered crime and police news.

Witnesses said that around 6:30 p.m., Lopez was in his office when a white vehicle carrying two men pulled up in front, Canseco Gutierrez said. One man got out, walked into the office and shot Lopez, he said.

Canseco Gutierrez said he had just had breakfast with Lopez on Wednesday. He said his friend had never told him he'd received threats, but he didn't doubt the killing had to do with his work.

He recalled that in June of last year, journalist Gustavo Sanchez Cabrera was killed by gunmen only about 20 minutes from Salina Cruz.

Lopez's murder follows those of four journalists in January.

On Jan. 31, Roberto Toledo, a camera operator and video editor for the online site Monitor Michoacan was shot by assailants as he prepared for an interview in Zitacuaro, Michoacan.

In the border city of Tijuana, crime photographer Margarito Martinez was gunned down outside his home Jan. 17. On Jan. 23, reporter Lourdes Maldonado Lopez was found shot to death inside her car also in Tijuana.

Reporter Jose Luis Gamboa was killed in the Gulf coast state of Veracruz in an attack Jan. 10.

Jan-Albert Hootsen, Mexico representative of the Committee to Protect Journalists, said via Twitter: "The first six weeks of 2022 have been the deadliest for the Mexican press in over a decade."