Egyptian authorities detained a Ukrainian tanker carrying Iranian oil as it passed through the Suez Canal ten days ago, Al-Araby Al-Jadeed has reported.

News of the seizure came a day after Egypt’s Supreme State Security Criminal Court sentenced six people to jail on charges of spying for Iran.

The court has sentenced the defendants to between 15 and 25 years in jail, a $30,000 fine and the confiscation of their computers and phones. Egyptian Al-Azhar Professor Alaa Moawad, who was present at the trial on Sunday, was accused of harming Egypt’s national interests and receiving money to spread Iranian Shiism in Sunni Egypt by launching a website, issuing publications and attracting recruits.

The remaining five defendants, who were Iranian, were tried in absentia.

The sentences have been issued amid rising tensions between Iran and the US, Egypt’s major ally, which is trying to force Tehran to renegotiate a 2015 nuclear deal by tightening sanctions on the country.

READ: US’ Pence vows to not let Iran get nuclear weapon

In response Iran said over the weekend that it is prepared to enrich uranium at any level and at any amount, according to Reuters.

Tension between the two countries is ongoing. In June Iran was accused of attacking oil tankers in the Gulf of Oman and later shot down a US drone reportedly launched from UAE territory. Tehran has denied targeting the tankers.

At the time UK Foreign Secretary Jeremy Hunt, also a major ally of the US and Egypt, stated that Britain would consider joining the US in potential military action against Iran.

Then last week Iran summoned the UK ambassador after the Royal Marines seized an Iranian supertanker off the coast of Gibraltar it suspected of carrying oil to Syria in contravention of sanctions against Bashar Al-Assad.

READ: UK cuts aid to northeast Syria citing fear of funding Daesh

Iran-Egypt relations are also tense due to Egypt’s support for the Saudi-led coalition against the Houthis in Yemen, who Riyadh accuse Iran of arming.

Last month Egypt said it was standing by Saudi Arabia following an attack by the Houthis that wounded over 20 people at an airport in the kingdom.

Cairo has joined Washington in calling on the Houthis to cease attacks and said it will “defy any attempt to target the kingdom.”