A home-made bomb exploded early Monday in the garage of a Communist Party official in the southern province of Binh Duong, but no one was hurt.
Police later found another bomb placed in one of his cars.
The official, Do Van Cong, a secretary of the Party's Binh Duong Province Committee, escaped both incidents unscathed.
The first bomb exploded at a round 3 a.m. in his garage, but caused almost no damage, according to local police.
Cong later spotted another suspicious object placed inside one of his cars, which police confirmed to be another explosive device.
The home-made bomb included 50 grams of explosives and a detonator connected to a mobile phone, police said.
Local newswire VnExpress quoted local police as saying that the mobile phone had recorded four missed calls, which may imply several attempts to trigger the bomb.
Police are investigating the incident.