Abdul Jabar Qahraman is the 10th candidate to be killed ahead of parliamentary polls boycotted by the Taliban.

An Afghan election candidate is among four people killed by a bomb planted under his chair in the southern province of Helmand days before the parliamentary elections, officials said.

Abdul Jabar Qahraman, who was preparing to contest Saturday’s elections, was killed in his office on Wednesday in the city of Lashkar Gah, a senior government official said.

Omar Zwak, a spokesman for the Helmand governor, said another seven people were wounded in the attack claimed by the Taliban armed group, which is boycotting the crucial elections.

“We are investigating the incident,” Zwak said.

The Taliban, in a statement released earlier in the day, warned teachers and students not to participate in the parliamentary elections due on October 20, and not to allow schools to be used as polling centres.

“People who are trying to help in holding this process successfully by providing security should be targeted and no stone should be left unturned for the prevention and failure [of the election],” Taliban spokesman Zabihullah Mujahid said in the statement.

Qahraman is the 10th candidate to be killed in the past two months. Another two have been abducted and four others were wounded in attacks.

More than 30 people have been killed in election-related violence over the past several weeks. The election for the 250-member parliament has been delayed by nearly three years.

Afghan has a presidential form of government but the parliament plays a crucial role in passing bills and ratifying international treaties.

Dozens of Afghan police were killed or wounded in heavy fighting in northern and central provinces overnight on Tuesday.

Helmand, bordering Pakistan, has long been one of the strongholds of the Taliban group, which has been waging an armed rebellion since they were removed from power in Afghanistan by US-led forces in 2001.