The bullet holes are a reminder of what happened here on Monday.

Islamic state militants have now claimed responsibility for this massive attack, in which a least 35 people were killed, most of them local students.

On Tuesday, defiant students gathered in a show of unity, some holding placards saying, Why are we being killed?

Things?

Protester tells us that students will never give up, no matter how much they try to kill us.

Some of the students have blamed the Taliban, although the Taliban have denied any involvement and condemned the attack.

According to Islamic state's Amaq news agency, It's gunmen targeted a gathering held to mark the completion of a training course.

President Ashraf Ghani is calling it a despicable act of terror and announced a national day of mourning.

This was the second attack on an educational institution in the capital.

In just over a week, the three gunmen was shot dead by Afghan security forces.