-LRB- CNN -RRB- -- Norway has condemned the ransacking of the Sri Lankan embassy in Oslo by Tamil demonstrators . The entrance to Sri Lanka 's embassy in Oslo on Sunday . Video posted on Norway 's TV 2 Web site showed demonstrators smashing through re-enforced glass at the embassy on Sunday . The aftermath showed embassy offices that had been trashed , with furniture , artwork and potted plants dumped on the floor . Countertops had been bashed and splintered . `` Please help the Tamils . Stop the massacre of Tamils , '' a sign carried by one of the demonstrators said . The foreign ministry said it has requested that police tighten security at the embassy , which is located in an office building . `` I deeply deplore the fact that unauthorized persons unlawfully forced their way into the Sri Lankan embassy in Oslo and caused extensive damage , '' said Foreign Minister Jonas Gahr Store . `` This is a violation of Norwegian law and an action that is totally unacceptable . '' Rohitha Bogollagama , Sri Lanka 's foreign affairs minister , called for authorities to `` seek immediate arrest of the perpetrators of this serious act of terror '' during a CNN interview in New Delhi , India . The attack came as Sri Lanka 's president ordered military troops to restrict their offensive against Tamil Tiger rebels while the nation celebrates the Sinhala and Tamil New Year . The two-day celebrations began Monday . The order was meant to allow the thousands of Tamils trapped by the fighting to travel for the New Year , said a statement from the office of President Mahinda Rajapakse . Troops are in the midst of an intense military push in northern Sri Lanka , where they have snatched back large swaths of land from the Tamil rebels . The rebels have fought for an independent homeland for the country 's ethnic Tamil minority since 1983 . The civil war has left more than 70,000 people dead . A statement on the Sri Lankan defense ministry Web site called on Norway to `` bring the perpetrators to justice immediately . '' `` The perpetrators can be readily identified on the CCTV recording which has been made available to the authorities , '' the statement said . `` The demonstrations , which had been building up in intensity in the past few days , provide an indication that something was being planned . '' CNN 's Harmeet Singh and Iqbal Athas contributed to this report