Oslo - Norway on Tuesday said it was deeply concerned over the situation for civilians in Sri Lanka after the recent government offensive against Tamil rebels.

Earlier Tuesday, some 200 Tamils gathered outside the foreign ministry in Oslo calling for an end to the fighting.

"Norway condemns the ongoing warfare in Sri Lanka and the unacceptable suffering for civilians," Foreign Minister Jonas Gahr Store said in a statement.

Store's cabinet colleague, Environment and International Development Minister Erik Solheim said he was "very worried" about the fate of the civilians trapped in areas where the fighting was raging in north-east Sri Lanka.

"Everything must be done to prevent the suffering of the population. We receive messages that the number of civilian casualties is growing, and that refugees are caught in the crossfire," Solheim added.

Norway in 2002 helped broker a ceasefire agreement between Colombo and rebels of the Liberation Tigers of Tamil Eelam (LTTE) that collapsed in 2006. (dpa)