MEXICO CITY, Dec. 14 (Xinhua) -- At least 17 people were killed and 20 others injured on Sunday after a bus plunged into a ravine in Colombia's northwestern department of Antioquia, local authorities said.

The bus departed from the tourist town of Tolu in the Caribbean department of Sucre and was transporting a group of students returning from an excursion. The accident, whose cause remains unknown, occurred in the municipality of Remedios in northeastern Antioquia, according to department governor Andres Julian Rendon.

"The entire department of Antioquia mourns the deaths of 17 people in the tragic bus accident involving students returning to the municipality of Bello after celebrating their graduation on the beaches of Sucre," Rendon said on the social platform X.

Three of the injured were in serious condition, he added. ■