The European Medicines Agency (EMA), the European Union’s drug regulator, on Friday found a possible link between Johnson & Johnson’s COVID-19 vaccine and rare cases of blood clotting in deep veins.

During a Pharmacovigilance Risk Assessment Committee meeting, the agency said it found a possible link between venous thromboembolism (VTE) and the J&J vaccine.

“VTE is a condition in which a blood clot forms in a deep vein, usually in a leg, arm or groin, and may travel to the lungs causing a blockage of the blood supply, with possible life-threatening consequences,” the agency wrote in its meeting highlights.