Afghan security forces arrested three senior ISIS members, including the group's regional leader, the government said on Monday. The militant group's head of South Asia, Abu Omar Khorasani, was detained in Kabul along with the group's spy chief and public relations officer, the General Directorate of National Security (NDS) and Interior Ministry said. "NDS will continue its comprehensive and targeted operations to hunt down senior leaders of regional terrorist groups and destroy the joint hubs of these terrorist networks," a joint statement said. ISIS has a small presence in Afghanistan, mainly in the north, although it has carried out high-profile attacks farther south in the capital. Afghan security forces arrested eight members of a network involving ISIS and Haqqani militants responsible for attacks in the capital including on Sikh worshippers, the country's security agency said on Wednesday. The violence underscored the challenges to securing lasting peace in Afghanistan even after the United States signed a troop withdrawal agreement with the Taliban in February. The Taliban, which said it opposed ISIS and has fought the group, has since held off on large-scale attacks on foreign forces or in major centres, although it has continued attacking Afghan security forces throughout the provinces. The arrest came on the same day that four back-to-back roadside bombs exploded in a northern district of Kabul, wounding four civilians including a child. Kabul police spokesman Ferdaws Faramarz said a clearance team was at the site of the attacks. Militants have carried out several roadside bombings and rocket attacks in Kabul and other parts of the country in recent weeks, but Monday's four consecutive explosions appeared to be the first coordinated effort for some months. The Taliban has not carried out any large attacks in the city since they signed a landmark withdrawal deal with the US in February, meant to pave the way for peace in the country. No group has claimed the attacks. Clashes in eastern Laghman province between security forces and the Taliban killed six security force members and wounded five, according to Haroon Yousufzai, a local military spokesman. The Ministry of Defence said the Taliban also suffered heavy casualties. The Afghan government and foreign powers including the US have been calling on the group to reduce violence, saying it is hindering progress on moving towards formal peace talks.