At least one person was killed and 14 wounded when a bus carrying workers at a small oil refinery in northern Iraq was blown up by an improvised explosive device, police said.
The bus was at the Siniya refinery, near Iraq's largest oil refinery of Baiji in the predominantly Sunni Salahuddin province, when it exploded, Baiji police said on Saturday.
Separately, three civilians and a policeman were injured when a parked car exploded in a market area in Fallujah within the western, also Sunni, Anbar province, security sources said.
No group has claimed responsibility for either attack, but ISIS militants are active in both provinces.
Iraqi forces declared victory over the hardline Sunni Islamist group in December after retaking all the territory it held in a four year war, but its fighters are waging a guerrilla-style insurgency.
Despite this, United Nations casualty figures for Iraq are at their lowest level this year since they began monthly publication in 2012. An estimated 75 Iraqis were killed and 179 injured in acts of terrorism, violence and armed conflict in September, according to the UN.
Security sources said the attack in Fallujah was the first since Iraqi forces retook the city from the militants in 2016.
It came only after Popular Mobilisation Forces (PMF), an umbrella network of mostly Shiite militias, started operating within the city, residents and tribal leaders said.
PMF forces have long been stationed at checkpoints around the city and in the entire province but had not entered the city proper before.