Juan Antonio Serrano, the brother of Ecuadorian Interior Minister Jose Serrano, was murdered Sunday and five people have been arrested in connection with the killing, the Andes news agency reported.

The 34-year-old victim was at the house of a relative in downtown Cuenca, a city in the Andean region of southern Ecuador, "when a group of anti-socials tried to enter the building and Serrano tried to stop them," Andes said.

"At that time, one of the subjects, still unidentified, stabbed him near the neck," the news agency said.

The assailants managed to get away from the house, but police launched an operation to find them, Andes said.

Officials have not yet commented on the murder, but the National Police posted a condolence message on its Twitter account.

Juan Antonio Serrano, the interior minister's younger brother, was a professional photographer.

Serrano was known for his documentary work, including a study of the streets of Beijing that he published with the title "Alguien te esta mirando" (Someone Is Watching You) in 2010 while on an internship with Agencia Efe's bureau in the Chinese capital.

He worked as a freelancer for Efe in Quito in 2007, 2008 and 2010.

The Interior Ministry called on the media in a Twitter post to not speculate about the killing and urged journalists "to report information released in an official form."

"They murdered a much-loved friend and former collaborator of the Foreign Ministry, Juan Antonio Serrano. An excellent professional and a great human being," Foreign Minister Ricardo Patiño said in a Twitter post. EFE