KABUL (REUTERS) - Afghan President Ashraf Ghani condemned Monday's (June 4) suicide bomb attack outside a peace tent gathering of Muslim clerics in Kabul and backed their fatwa against suicide attacks, saying they violated the tenets of Islam.

The bomb killed 14 people, including seven clerics, and was the latest in a series of attacks that have underlined the deteriorating security ahead of parliamentary and district council elections set for Oct 20.

"The attack that targeted the large gathering of clerics and religious scholars from across the country was in fact an attack against the heirs of the prophet of Islam and the values of Islam," Ghani said in a video address, supporting the outlawing of suicide bombings.

"Unfortunately, the imposed war in Afghanistan every day takes lives of our innocent children."

The Islamic State in Iraq and Syria (ISIS) militant group, without providing evidence, claimed responsibility for the attack.

The Taleban, seeking to reimpose strict Islamic rule after their 2001 ouster by US-led forces, denied involvement, but blamed the "American process".

More than 2,000 religious scholars from across the country met on Sunday and Monday at the Loya Jirga (Grand Council) tent, denouncing years of conflict. They issued a fatwa, or religious ruling, outlawing suicide bombings and demanding that Taleban militants restore peace to allow foreign troops to leave.

A series of bombings in Kabul has killed dozens of people in recent months and shown no sign of easing during the Muslim holy month of Ramadan.

There was an explosion near a girls' school in the eastern province of Nangarhar early on Tuesday (June 5) but no one was hurt, a provincial education official said. The school had announced two days off after receiving threats.

Spreading violence by Taleban and other militant groups has forced many schools to close, undermining fragile gains in education for girls in a country where millions have never set foot in a classroom.

Nearly half all children in Afghanistan are out of school due to conflict, poverty, child marriage and discrimination against girls, the number rising for the first time since 2002, humanitarian organisations said in a report on Sunday.