Ankara, May 18 (IANS/EFE): Two parcel bombs exploded simultaneously on Monday in the offices of the opposition Peoples' Democratic Party (HDP) in two Turkish cities, injuring at least eight people, three of them seriously, according to reports by CNN Turk.

The two explosions, one at the election office in Mersin and the other in Adana (both in the south, bordering the Mediterranean), took place on Monday morning, less than 20 days before Turkey's general election on June 7.

Six people were wounded in Adana, three of them critically, while two were wounded in Mersin, according to Hurriyet newspaper.

In protest against the attack, a group of HDP followers gathered on Monday morning in front of the Mersin office.

During the ongoing election campaign, 50 attacks on HDP centres have already been reported, which the opposition party blames on the ruling Justice and Development Party (AKP).

The leftist and pro-Kurdish HDP poses the greatest electoral threat to the ruling AKP as, if it exceeds the minimum parliamentary representation of 10 percent, the ruling party will lose a large number of seats.