A senior advisor to Turkish President Recep Tayyip Erdogan has said he would personally defend the head of state with his own weapons and ammunition, as political tensions intensify ahead of June 7 elections.

"I have two licensed guns and hundreds of bullets which I've had for years because of my rights," Yigit Bulut, chief economic advisor to Erdogan, told a live show broadcast on state-run TRT Haber late Tuesday.

Twin bomb attacks on Monday hit the regional headquarters of Turkey's main pro-Kurdish party in two cities, injuring more than half a dozen people and escalating tensions ahead of June 7 legislative elections.

Six people were injured in the blast at the office of the People's Democratic Party (HDP) in the southern city of Adana caused by a suspect parcel, three of them seriously, a party official told AFP.

Turkish armed forces on Saturday shot down a Syrian helicopter that violated Turkey's airspace in the south of the country, the Turkish defense minister said.

"A Syrian helicopter was downed that violated the border for a period of five minutes within a seven mile (11 kilometer) limit," Defence Minister Ismet Yilmaz was quoted as saying by the Dogan news agency.

Turkish President Recep Tayyip Erdogan on Saturday attacked the death sentence handed out by an Egyptian court to former president Mohamed Morsi, saying it was like a return to "ancient Egypt".

"The popularly-elected president of Egypt... has unfortunately been sentenced to death. Egypt is turning back into ancient Egypt," Erdogan said at a rally in Istanbul, accusing the West of "turning a blind eye" to the 2013 coup that ousted Morsi.

Turkey has placed under arrest the powerful former police chief of the southeastern city of Diyarbakir and nine others as part of a case into eavesdropping of top officials, reports said Saturday.

Recep Guven, who headed police in Turkey's biggest majority Kurdish city, is accused with abuse of office in bugging the communications of dozens of politicians, presidential advisers and journalists without observing proper procedure.

Turkey's top judicial body on Tuesday expelled four prosecutors and a judge who oversaw a massive corruption investigation that tarnished the Islamic-rooted government and reached into the inner circle of President Recep Tayyip Erdogan.

The Supreme Board of Judges and Prosecutors (HSYK) voted to bar prosecutors Zekeriya Oz, Celal Kara, Muammer Akkas and Mehmet Yuzgec, as well as judge Suleyman Karacol, state-run Anatolia news agency reported.

Turkey's President Recep Tayyip Erdogan on Sunday rallied thousands of supporters in Germany, weeks before his Islamic-rooted party will contest June parliamentary elections.

"The ballot box is your weapon," Erdogan told the crowd of over 14,000, who waved Turkish flags and shouted "We love you Erdogan, we are proud of you!" national news agency DPA reported.

Turkish President Recep Tayyip Erdogan has controversially turned religion into a campaign issue in the officially secular country's upcoming polls, which promise to be the biggest election challenge yet for the ruling party.

In an unprecedented gesture by a Turkish politician in recent times, Erdogan waved a copy of the Muslim holy book the Koran translated into Kurdish during a rally this week in the Kurdish-majority southeast.

The top U.S. diplomat to Turkey on Monday called for the protection of fundamental freedoms, no matter whether the NATO ally is ruled by a presidential or parliamentary system.

Ambassador John Bass said it was up to the Turkish people to decide which system they preferred, amid a debate over how the country should be governed ahead of a key parliamentary vote in June.

Turkey on Friday was holding in detention two judges who issued a controversial release order that would have allowed the liberation from custody of dozens of opponents of President Recep Tayyip Erdogan, the official Anatolia news agency reported.

Judges Metin Ozcelik and Mustafa Baser at the weekend issued an order to release the 74 former police and the head of the Samanyolu TV channel Hidayet Karaca from police custody.