A military and police operation targeting a militia in western Kenya continues. As Derek Kilner reports from Nairobi, journalists are complaining that they are still being barred from the areas affected by the operation.

The two-week-old operation is targeting the Sabaot Land Defense Force, a militia that has been implicated in land clashes in the Mount Elgon region of western Kenya that have killed several hundred people in the past two years.

The group was blamed for killing 13 people in an attack on two villages earlier this month. This week 150 people were charged in court with ties to the militia.

Throughout the operation, media outlets have complained that the military has blocked access to the Mount Elgon area and harassed journalists trying to cover the story.

Earlier this week, the international press freedom group Reporters Without Borders criticized the Kenyan army's conduct. Leonard Vincent is head of the organization's Africa desk.

"This behavior is a matter of concern for us because it has reached a level of brutality that we have not seen before," he said. "Especially on March 12 where a TV team and Nation Media Group journalist were arrested, forced to kneel down and were slapped several times. This is something that is absolutely not tolerable in a democratic country."

Defense Department spokesman Bogita Ongeri, meanwhile, denied wrongdoing on the part of the military.

"I really do not think that we have mishandled journalists," he said. "That military operation is an area where you need to get clearance because you never know what will happen. Journalists can cover what is happening but what we want is just coordination."

But David Matende, Chairman of the Kenya Union of Journalists, says journalists are still being prevented from accessing the Mount Elgon area and that coverage of the operation has suffered as a result.

"Our people cannot access that region," said Matende. "They have been stopped by the military to access the area of conflict. In Kenya, when there is a security operation they used that blanket excuse to stop the media and everybody else from accessing the place. The information now being published by reporters is the official information, the one given by officials."

Matende says journalists have been barred from other internal security operations in the past.

In addition to the Sabaot Land Defense Force, the current operation is targeting other smaller armed groups, including the Moorland Defense Force and the Political Revenge Movement.

As with other clashes over land in Kenya, the fighting around Mount Elgon is not new, but the level of post-election violence that followed December's disputed elections appears to have given renewed urgency to the need to tackle such disputes.