HERAT, Afghanistan (Reuters) - Up to 17 members of the Afghan security forces were killed on Sunday in Farah province on the border with Iran, according to officials in the region, where the Taliban have been pressuring government forces for months.

Officials said the casualties occurred in different incidents late on Sunday night as insurgents kept up attacks on security checkpoints in vulnerable districts.

Mohibullah Mohib, a spokesman for the provincial governor, said Taliban fighters attacked security forces in Pusht-e Rod district, in the west of the province, killing five police.

However a member of the local provincial council, Fareed Bakhtawar, said 10 police were killed in Pusht-e Rod, while another seven soldiers were killed in the district of Bala Boluk, where the insurgents have tightened their grip this year.

The government no longer releases combined casualty totals but there has been a nearly constant stream of similar fighting that has chipped away at the strength of Afghan security forces, often stationed on vulnerable checkpoints.

Farah province, a remote desert area of smuggling routes and uncontrolled borders, has seen constant fighting this year and in May, the insurgents even briefly overran the provincial capital before being driven back with the aid of U.S. forces.