Switzerland has called on the warring parties in Sri Lanka to respect human rights and to declare a ceasefire.
A statement issued by the foreign ministry on Thursday spoke of the country's "deep concern" at the humanitarian situation in the north of the island.
It said 200,000 civilians were caught in the crossfire, and that international law was being ignored. A "disproportionate use of force" had already caused many civilian casualties.
The statement also called for an immediate cessation of hostilities and for a negotiated settlement.
Sri Lankan government forces recently launched an offensive against Tamil Tiger rebels who have been fighting for a separate Tamil state in the north and east of the island for 37 years. They say they are discriminated against by the Sinhalese majority.
Throughout the period, both sides have been accused of serious human rights violations.