A suicide car bombing killed at least six people early Monday at Jalalabad airport in Afghanistan.

The Afghan Taliban claimed responsibility for the attack, which occurred at the gates of the airport. The causalities in the attack were all civilians, BBC reported, citing provincial police officers. Several other people have been wounded in the attack.

Violent protests have been raging in Afghanistan for days after it emerged last week that copies of the Islamic holy book, the Quarn, were burned at a U.S. military base near Kabul. The U.S. officials in Afghanistan have said the books were accidentally burnt.

According to the Voice of America, more than 30 people have died in protests related to the Quran bombing.

Afghan authorities are still searching for a policeman who is suspected to have shot and killed two American military personnel inside a high-security room in a government ministry. The Afghan Taliban claimed the ministry attack, which killed a U.S. colonel and a major, and said the attack was in retaliation for the Quran burning.

In another incident on Sunday, seven U.S. military personnel were killed in a grenade attack at a U.S. base in the Kunduz province.