Gunmen killed at least 12 fieldworkers on a Liberian farm over the weekend, police said Wednesday.

The attackers set upon the group as they were clearing the fields for planting, adding that they believe the attack was linked to an ongoing land dispute, Police Chief Beatrice Munah said.

The bodies were found in the Farmington river near where Saturday's attack took place, Munah said. The farm is about 55 kilometers (35 miles) south of the capital, Monrovia.

During years of on-and-off war, much of Liberia's population fled and property records were lost. The West African country has been working to rebuild since 2003, but fights over land ownership have continued to erupt.

Munah said divers are searching to see if there are any more bodies.

She declined to say if any arrests had been made, saying the investigation was ongoing.

One of the workers who escaped, Tidoe Monden, said nearly 50 people were working in the field when armed men arrived Saturday morning and started shooting.

"We just saw suppressive gunfire from all directions," 41-year-old Monden said. He said the attackers used some of the workers' machetes to "finish some of the wounded" then threw the bodies into the river.

The farmland on which the killings took place is claimed both by Charles Bennie, an ex-rebel spokesman and ex-government official, and by Roland Kaine, a current senator from the region.

Monden said Bennie had trucked him and the other workers in to start preparing the farm for planting. Bennie has accused Kaine of instigating the attack, but Kaine denied any knowledge of it.