"In Iran, an estimated 100,000 people left Tehran in the first two days following the attacks," UNHCR, the UN refugee agency, said in a situation report.

"Latest reports indicate no increase in cross-border movements linked to recent events. The situation at the Islam Qala border crossing with Afghanistan remains stable with no significant changes observed," it said.

Sparked by a massive US-Israeli attack that killed supreme leader Ayatollah Ali Khamenei, the war has seen Iran lash out with missile and drone strikes from Israel across the Gulf.