Hopes of finding more survivors of the powerful earthquake ‌that rocked Colombia early this week were fading on ⁠Thursday as rescue workers narrowed their searches, while families in the worst-hit areas waited for news of missing relatives.

In Cali, the country's third-largest city, crews shifted from a search-and-rescue effort to debris removal at most sites, a sign the disaster response was entering a grimmer phase after the crucial first 72 hours.

"Unfortunately, we ‌are reaching a point where the likelihood of finding survivors is dwindling, but ‌our mission is to keep searching and find all those people who are reported missing," David ‌Tamayo, head of Colombia's National Unit for Disaster Risk Management, said on Thursday evening.

The magnitude-7.5 quake struck shortly after 7:30 a.m. local time on Monday, toppling apartment ‌blocks, damaging homes, schools and hospitals, sending residents into the streets across western Colombia, home to the country's coffee farms.

At least 281 people were killed – many in Cali and Pereira, a city in the coffee region – and more than 3,900 injured, according to government data on Thursday evening. The data indicated 379 people were still reported to be missing.

UN Under-Secretary-General for Humanitarian Affairs Tom Fletcher has allocated $5 million from the UN Central Emergency Response Fund to support earthquake relief efforts in Colombia.