Phnom Penh  - A senior Cambodian journalist working for an opposition newspaper was gunned down and killed in a central street in the capital Friday evening, police said.

Khim Sam Ol was a journalist for the pro-Sam Rainsy Party newspaper Moneaksekar Khmer, police and a journalism representative said.

Police said Sam Ol's son, who was not named, was also seriously injured in the attack as the pair walked back from exercising at the capital's Olympic Stadium after work.

Ages of the men were not immediately available.

Cambodia is scheduled to hold national elections on July 27 and although the National Election Committee has reported fewer potentially politically motivated incidents than previously, past pre-election periods have been marked by violence.

The murder is likely to cause a political storm because on June 8, Sam Ol's editor, Dam Sith, was arrested on defamation charges against Deputy Prime Minister Hor Namhong and spent a week in Prey Sar prison before Prime Minister Hun Sen intervened.

Hor Namhong later dropped the charges after Dam Sith wrote to him saying he had made "a mistake" in publishing the offending comments.

And police Friday urged caution in assigning political blame to Sam Ol's murder, saying investigations were in the early stages and no motive had been established.

"If you don't like someone, hurting them when tensions are high, like before an election, and then hoping politics is blamed is a sensible strategy," one officer said on condition of anonymity.

Personal disputes, most often over money, land or lovers, remain by far the primary motives for murder in Cambodia. (dpa)