The Roman Catholic Church and a media watchdog called for justice Wednesday after an anchorman of a Catholic-run radio station was killed by motorcycle-riding gunmen in the southern Philippines.

Colleagues said they were puzzled by Tuesday's killing of Radio DXHM broadcaster Nestor Sapidan Libaton along a remote section of a highway in Mati city. Unlike many other journalists who came under attack after exposing corruption or drug trade, he wasn't handling sensitive topics or calling attention to officials.

"He was not even a hard-hitting commentator," said newswriter and fellow anchor Leonila Duallo.

Police said they were investigating.

Duallo said their three radio shows dealt with routine regional and local government affairs. The programs were government-sponsored. Duallo and Libaton co-anchored with another colleague, Eldon Cruz, who was driving the motorcycle on which Libaton was riding.

Libaton and Cruz were heading back to Mati after covering an agricultural fair in another town when they heard gunfire from three men on another motorcycle behind them. Cruz maneuvered to evade the gunmen but for unknown reasons Libaton got off and was shot six times, Duallo told The Associated Press by phone.

He died on the spot and Cruz was unharmed, Duallo said.

Archbishop Jose Palma, president of the Catholic Bishops Conference of the Philippines, called on authorities to pursue justice.

"We are saddened because we know how important communication is," he told church-run Radio Veritas in Manila.

The U.S.-based Committee to Protect Journalists also urged authorities to bring the perpetrators to justice. The watchdog says Libaton is the second media worker killed in as many weeks. It is not clear that the case involving Michael Jayson Calanasan, a reporter for a local newspaper who was killed April 24 in Laguna province south of Manila, was work related. He also worked for the local city hall.

The Philippines has one of the world's highest rates of unsolved media killings. At least 151 reporters have been killed since 1986, including 32 in 2009 in the single worst media killing anywhere in the world when suspected political clan members ambushed a rival's convoy.