Colombo (Reuters): The United Nations on Wednesday raised concern for the safety of Rohingya Muslim asylum seekers in Sri Lanka after Buddhist monks and hard-line nationalists forced them to flee a UN shelter in the capital Colombo.

The refugees, who were detained in April along with two suspected Indian human traffickers in a boat off Sri Lanka’s coast, are now in a camp in southern Sri Lanka to ensure their security after the incident in the capital.

In Tuesday’s incident, the Sri Lankan monks and nationalists stoned the shelter, prompting its 31 Rohingya occupants — mainly women and children — to flee for their own safety, witnesses said. No injuries were reported.

In a statement, the UN High Commissioner for Refugees said the incident was alarming, saying the refugees had been victims of violence and persecution in Myanmar, from which some 422,000 Rohingya have fled to nearby Bangladesh over the past month.

“UNHCR emphasises that [the] refugees ... need international protection and assistance. UNHCR urges the public and all those concerned with refugees to continue extending protection and to show empathy for civilians fleeing persecution and violence.”

It said the Rohingya had been staying in Buddhist-majority Sri Lanka with the Colombo government’s approval and UNHCR was providing assistance “until longer-term solutions can be found”. President Maithripala Sirisena’s government condemned the attack on the refugees as “shameful” and urged police to hunt down the perpetrators.

Witnesses said the monks stormed into the safe house chanting, “Rohingyas are terrorists” and accusing them of having killed Buddhist monks in Myanmar.