BOGOTA (Reuters) - Colombia’s foreign ministry said on Tuesday it had sent a letter of protest to Venezuela, accusing it of allowing helicopters and soldiers to cross the shared border without permission over the weekend.

“There was a violation to Colombia’s sovereignty on the part of two military helicopters, identified with the acronym of the Bolivarian National Guard, and some 30 armed soldiers,” Colombia’s foreign ministry said in a statement.

The ministry sent a letter to the Venezuelan embassy in Bogota expressing its “most energetic protest” against the incident, which took place in the Tibu municipality in Norte de Santander province on Sunday, the statement added.

The Venezuelan government did not immediately respond to a request for comment.

Venezuelan soldiers have repeatedly crossed into Colombia without permission, exacerbating long-standing tensions between the neighbors. Colombia is a top destination for Venezuelans fleeing food and medicine shortages amidst their country’s deep economic crisis.