Trinidad and Tobago Coast Guard officers fired at a boat carrying Venezuelan migrants Saturday night, wounding a mother and killing the baby in her arms, authorities said Sunday.

The fatal shooting took place as officers tried to stop a boat crossing the Venezuelan border into Trinidad and Tobago, in what the island nation’s officials described as an act of self-defence, according to a Coast Guard statement.

Venezuelan human rights lawyers and opposition officials condemned the shooting and demanded an investigation.

“The death of a Venezuelan boy, who along with his mother fled from the dictatorship, hurts our soul as a country,” tweeted Venezuelan opposition leader Juan Guaidó. “The shots fired by the Trinidad and Tobago Coast Guard are unjustified; they killed him.”

The Coast Guard spotted the boat as it crossed the Venezuelan border into Trinidad and Tobago waters just before midnight Saturday, according to a statement posted on Facebook and signed by Kerron Valere, a lieutenant and public affairs officer with the Trinidad and Tobago Coast Guard.

The Coast Guard crew tried to intercept the boat using its horn, searchlight and flares, followed by warning gunshots, according to the statement. Still, the ship continued forward with “aggressive” moves, attempting to ram into a Coast Guard vessel.

The vessel was more significant than the Coast Guard boat, the statement said, and its advances caused crew members “to fear for their lives,” prompting them to fire shots at the vessel’s engine, according to the Coast Guard statement, which did not specify how many shots were fired. Officials said the recent use of this “evasive technique” against the Coast Guard in other instances had caused ship damage and risked the safety of crew members.

Only after the ship stopped did the Coast Guard realise there were migrants “hidden” on board, and a woman was bleeding, according to the statement. The woman was stabilised and taken to a local health facility, but her baby was found unresponsive. Officials did not specify how many people were on the vessel but said the others on board would be processed “following immigration and health protocols.”

“The Trinidad and Tobago Coast Guard extends sincerest condolences to the family and loved ones of the infant and takes the opportunity to wish the injured female a speedy recovery,” the statement read.

The wounded mother told her relatives that the boat captain wanted to turn back to Venezuela when he saw the Coast Guard, the woman’s sister-in-law, Daicelis Salgado, 38, said in an interview with The Washington Post.

“But the Guard followed them and started shooting at the engines,” Salgado said. “She was close to the engine. She said she felt something hit her in the chest and immediately looked down and saw the baby’s head broken. She had him in her chest when she was shot.”

The baby, his mother and his sister were all on their way to meet the children’s father, who had been living in Trinidad, Salgado said. She said authorities have not yet informed the father or other family members of the whereabouts of the older child or the body of the baby boy.

“My brother doesn’t know where his daughter is,” she said.

Salgado left for Trinidad four years ago from her hometown in Venezuela, fleeing the economic crisis. Her brother followed eight months ago. She learned the rest of his family was travelling to Trinidad this Saturday.

“I told him I didn’t agree because things are not very good here now,” she said. “But he told me he rented a room and bought a fan for his children. He wanted them all to be together.”

They were among 20 people on board the migrant boat on Saturday night, said Orlando Moreno, a lawyer with the Venezuelan advocacy group Foro Penal. He heard about the death of a family member of the baby boy in Trinidad on Sunday.

“What kind of people are they to shoot like that? What consolation can a mother have after that?” Moreno said in a tweet, adding that he has put the relatives in contact with United Nations representatives in Venezuela. “This is the reality of our coasts. It is a permanent tragedy with faces, stories, families and pain.”

Between six to 10 vessels leave daily from northeastern Venezuela toward Trinidad and Tobago, Moreno said, as Venezuelans continue to flee the economic crisis in the socialist state under the government of President Nicolás Maduro. The president did not make any public statements about the shooting late Sunday.

The fatal shooting comes as Venezuelans cross into the United States in record numbers, usually after flying to Mexico and walking across the border. U.S. Customs and Border Protection stopped 24,819 Venezuelans in December, up from 206 a year earlier.

Nafeesa Mohammed, a human rights attorney in Trinidad, said she was concerned about the shooting and described it as an “abnormal situation” with more questions than answers.

“It is a very barbaric approach,” she said.“You should not be firing at a vessel in the middle of the night unless attacked. … Was there evidence of an attack? Who can prove it?”