The crew of the Golfo Azzurro, the migrant rescue vessel belonging to Spanish NGO Proactiva Open Arms, was arrested by the Libyan coastguard and detained for several hours only a short time after claims they had turned off their transponders.

The Spanish-based NGO took to Twitter to claim the Libyan coast guard had boarded their vessel and was holding them at gunpoint. They wrote that the Libyan authorities were “seizing” the vessel and said: “They threaten to shoot if we do not follow orders.”

The group released a picture of the Libyan vessel as well as an image of the coordinates of their ship.

#URGENTE #ESTAPASANDO Secuestro #GolfoAzzurro Aguas Internacionales por Guarda Costas libios.Amenazan con disparar si no seguimos órdenes pic.twitter.com/0vY5Kbt0Wp — Proactiva Open Arms (@openarms_fund) August 15, 2017

Founder of Proactiva Open Arms Oscar Camps also wrote on Twitter that the Libyans had told the ship to set sail further off the coast into international waters or face the possibility of being fired upon. In the tweet, he posted an image showing the NGO vessel operating just outside of the Libyan territorial border.

Amenazados con abrir fuego si no ponemos rumbo a sus aguas territoriales, es un secuestro en toda regla. pic.twitter.com/QqVUqwlzrX — Oscar Camps (@campsoscar) August 15, 2017

The incident comes only hours after a tweet from the hipster-right Identitarian youth movement’s Defend Europe mission posted that they had observed the Golfo Azzurro and claimed they had turned off their transponder.

We just encountered the Golfo Azzurro, with its transponder turned off. Any planned meeting?#ExposeNGOs — Defend Europe (@DefendEuropeID) August 15, 2017

Turning off the transponder of their ship would also violate the code of conduct drafted by the Italian government earlier this month which stipulates a number of points NGOs must agree to or face not being allowed to dock in Italian ports.

Defend Europe also claimed that they were in contact with the Libyan vessel saying they told the NGO to leave the search and rescue (SAR) zone. On Twitter, Defend Europe said they also offered to cooperate with the Libyan authorities.

A captain of the libyan coastguard contacted us and stated that they have the same goals as #DefendEurope. We offered our cooperation. — Defend Europe (@DefendEuropeID) August 15, 2017

The incident is not the first time the Golfo Azzurro and her crew have come into conflict with the authorities.

Last week, the Libyan coastguard fired warning shots in the vicinity of the vessel and told the crew over the radio, “We have been watching you for the last two days. You are carrying out suspicious activities, we have confirmation that you have dealings with traffickers, do not come back to our waters.”

“Never come back, otherwise I will shoot you,” they added.

Earlier this month the ship was also denied access to the Italian port in Lampedusa after the Italian coast guard claimed they had violated the code of conduct.

Since the start of the Identitarian-led Defend Europe mission, authorities have started to be more firm with the migrant rescue NGOs. The pressure has led Médecins Sans Frontières (MSF), Sea Eye, and Save the Children to all suspend their operations in the Mediterranean. MSF claimed that the situation was simply too dangerous for the activists to continue their work.

Defend Europe, along with some Italian prosecutors, have alleged that the NGOs are working with people smugglers. The accusations have led to the German NGO Jugend Rettet having their ship, the Iuventa, confiscated and the Italians releasing photographs which they claim show the group working with smugglers.