Bombings across Iraq Tuesday killed at least 40 people and wounded nearly 100 others.

The bloodiest attack was in the southern Iraqi city of Diwaniya, where a bomb hidden in a vegetable truck exploded at a crowded market, killing 25 people.

Authorities declared a partial curfew in the city.

Earlier Tuesday, at least four people died when a pair of car bombs targeting Shi'ite pilgrims exploded near the central city of Karbala. The attack comes days ahead of ceremonies in Karbala to mark the birth of a key Shi'ite imam.

Bombs also rocked others areas of central Iraq, including the Sunni city of Taji.

No one has claimed responsibility for any of the bombings.

Violence in Iraq has increased in recent weeks, with attacks in June killing at least 237 people and leaving many Iraqis wondering if their government is able to guarantee security since the departure of U.S. troops.