Editor's note: A suicide bomber blew himself up outside a mosque following morning prayers in Afghanistan's northern Faryab province.

Here are the latest developments on this story.

[Updated 4:54 a.m. ET]  The death toll in a suicide bombing outside a mosque following morning prayers in Afghanistan's northern Faryab province, has risen to 40, including children and police, Lal Mohammad Ahmadzai, the spokesman for the northern Afghanistan police chief, said.

[Posted 3:14 a.m. ET] A suicide bomber blew himself up outside a mosque following morning prayers in Afghanistan's northern Faryab province, killing at least 30 people, according to a spokesman for the Ministry of Interior.

More than 50 people were wounded in the blast that came as worshipers finished prayers to mark the start of the Muslim holiday of Eid al-Adha, spokesman Sediq Seddiqi said.

The casualty toll is likely to climb given the size and timing of the explosion, Seddiqi said.  The attack occurred at a gate leading away from the Eid Gah Mosque in the provincial capital of Maimana, he said.