The son of former top Gulf drug cartel boss Antonio Ezequiel Cardenas Guillen was captured by marines, the Mexican Navy Secretariat said Tuesday.

Ezequiel Cardenas Rivera was detained last Friday along with four associates while he attended a party at a house in Matamoros, a border city in the northeastern state of Tamaulipas, the secretariat said.

The arrest of Cardenas Rivera, known as “El Junior,” was made possible by a tip and “naval intelligence work,” the secretariat said, without explaining why it waited four days to announce the capture.

The suspects, who were armed, were detained as they started to drive away from the house “in a hurry,” the Navy Secretariat said, adding that no shots were fired in the operation.