Turkey has announced it is extending a gas exploration mission in a disputed area of the Mediterranean Sea until November 4, in a move that is set to heighten tensions with Greece.

In a statement late Saturday, Turkey said the Oruc Reis seismic survey vessel, accompanied by two support ships — the Ataman and Cengiz Han — will operate in the area south of the Greek island of Rhodes for an additional week. An earlier notice had said the ships would only be operating in the area until October 27.

Read more: Germany warns Turkey against provocation in Mediterranean

The two countries are locked in a dispute over the extent of their continental shelves and conflicting claims to hydrocarbon resources in the eastern Mediterranean. The row began in August when Turkey sent the Oruc Reis into waters also claimed by Greece and Cyprus. 

Fears of military confrontation

The move sparked a dispute that threatened military confrontation between the NATO allies and drew widespread condemnation from the European Union. Ankara withdrew the Oruc Reis last month to allow for diplomacy before a European Union summit, where Cyprus proposed sanctions against Turkey. 

After the summit, the EU said it would punish Turkey if it continued its operations in the region. Ankara said the bloc's decision have put further strain on Turkish-EU ties. 

Greece and the European Union consider Turkey's drilling in the eastern Mediterranean to be illegal. Ankara contests it is working in its own exclusive economic zone.

The ship was sent back into the disputed waters this month, spurring condemnation from France, Germany and Greece.  

Concerns remain high that Greece and Turkey could engage in military conflict, as both have carried out maneuvers in the region with frigates and fighter jets involved. 

In the past, Turkey has dispatched other exploratory missions for oil and gas reserves in waters that Cyprus claims as its own. 

On Friday, the two NATO partners canceled planned military exercises for the coming week, which was seen as a sign of relaxation in the region.

lc/sms (AP, Reuters, dpa)