A gunman Monday fatally shot a radio broadcaster who had been critical of corrupt officials in the southern Philippines, and police captured the fleeing assailant with the help of passing firemen and bystanders.

Jerry Ortega, a hard-hitting anchor of a morning radio show on DWAR station in Palawan, was buying clothes at a store in Palawan's Puerto Princesa city after his radio work when a man approached and shot him once in the back of the head, killing him instantly, police Superintendent Rolando Amurao said.

Firefighters aboard a passing truck heard the gunfire then saw a man run from the scene and drop a pistol into a trash can. Using the firetruck's loudspeakers, the firemen alerted pedestrians and a police officer, who grabbed the fleeing man and recovered the .45 caliber gun, Amurao said.

The arrested man, who witnesses identified as the gunman, was being investigated, he said.

The National Union of Journalists of the Philippines says Ortega was the 142nd journalist killed in the country since democracy was restored in 1986.

The Philippines is considered one of the most dangerous places for reporters.

In the single worst killing of media workers in the world, 32 journalists and their staff were gunned down with 25 other people in what is believed to be an elections-related attack in southern Maguindanao province in 2009.

Ortega, who also had worked as a veterinarian and head of a crocodile-breeding farm, strongly criticized provincial officials linked to corruption and opposed the operation of mining companies in resource-rich Palawan, about 220 miles (350 kilometers) southwest of Manila, according to media colleagues.

Amurao said Ortega had received death threats from unknown people before the attack.