The number of people who have fled Nagorno-Karabakh for Armenia has risen to nearly 30,000.
A quarter of the 120,000 ethnic Armenians living in the region have left since the Azerbaijan military swept in and took control last week.
Azerbaijan assured residents they would be safe, but Armenia’s prime minister said “ethnic cleansing” was underway in the area.
A massive fuel blast killed at least 68 people attempting to flee.
Nearly 300 more were injured and 105 are missing.
It is not yet clear what caused the explosion evening near the main city of Khankendi, known as Stepanakert by Armenians, but many were refilling their cars.
As they crossed the border, thousands of Ethnic Armenians were subject to rigorous checks from Azerbaijani border control.
Azerbaijani authorities claimed to be looking for “war crimes” suspects, and one government source told Agence France Presse news agency that the country intended to apply an “amnesty to Armenian fighters who laid down their arms in Karabakh”.