Kabul, Dec 27 (IANS): The spokesperson for the Islamic State militant group in the Afghanistan-Pakistan region has been killed in an airstrike by the US forces, the Afghan Defence Ministry said on Thursday.

Sultan Aziz, the outfit's spokesperson for the so-called Khorasan province -- which includes Afghanistan, Pakistan and parts of Iran -- was hit in Nangarhar province in eastern Afghanistan, the Ministry's 201st Selab Military Corps said in a statement.

"(He) was killed in Pachir-Agam district of Nangarhar province two days ago by the US drone strike," said the statement cited by Efe news.

Aziz was also in-charge of recruiting fighters to carry out "deadly terrorist attacks against civilians".

Nangarhar, bordering Pakistan, has been a known bastion of the Islamic State since the group sprung up in Afghanistan in 2015.

Although over the last two years, the presence of its fighters has considerably reduced in other Afghan provinces, the group continues to remain active in Nangarhar and has claimed among the bloodiest attacks in the country.

According to the latest UN Assistance Mission in Afghanistan report, between January 1 and September 30 this year, Nangarhar, for the first time, overtook Kabul as the province with the highest civilian casualties with 554 dead and 940 wounded.

Across the country, 25 per cent of all casualties during this period were attributed to the Islamic State, while the Taliban was held responsible for 35 per cent.