Spanish NGO, Proactiva Open Arms, said Tuesday that its ship (Golfo Azzurro) had been seized for two hours by the Libyan coastguard in international waters, according to Agence France-Presse.

The NGO said its ship was 44.5 km off Libyan coast when the Libyan coastguards had seized it.

"The ship was sailing within the 100 miles zone that was created by the Libyan authorities last week, when the Libyan naval force and coastguards said their aim was to ban NGOs' vessels from search and rescue operations, accusing them of being accomplices to the human traffickers." AFP added.

Founder of Proactiva Open Arms, Oscar Camps, tweeted Tuesday that Libyan coastguards threatened to open fire on the ship if it did not return with them to the Libyan waters, adding that they backed off after one hour and 44 minutes in custody.

A photographer for Reuters aboard the ship said Libyan coastguards intercepted the ship, ordering it to sail to Tripoli or risk being targeted.

Defend Europe Association, which is opposed to the NGOs working in rescue operation, said its ship heard the Libyan coastguards warning Golfo Azzurro to leave Libyan waters or follow them to Tripoli.

Libyan Navy had announced, at the beginning of August in a presser at Tripoli Naval Base, the creation of a search and rescue zone in its waters banning all foreign vessels, especially those of the NGOs, from operating in it unless they had obtained a permit from the Libyan authorities.