Two police have been killed and four others injured in a suicide attack in Nawzad district of Afghanistan's southern Helmand province.
Police say the suicide bomber exploded an explosive-rigged car next to a police checkpoint. The bomber also died in the blast.
Afghan authorities have blamed Taliban militants for the attack.
Earlier that day, five bombers were killed and three soldiers were injured during a suicide attack on an army base in the province.
The attacks come hours after two separate attacks targeted diplomatic personnel in the Afghan capital of Kabul, including an attack on a vehicle belonging to the British embassy.
The four attacks have cost the lives of 17 people including 10 suicide bombers since Thursday.
Attacks across the country have increased in recent weeks as US-led NATO forces prepare to wrap up a 13-year combat mission against the Taliban.
Thousands of US and NATO troops are going to remain behind in a supporting role.
For more on the violence in Afghanistan, we earlier spoke with Professor Wang Dehua, Director of the Shanghai Institute for International Strategic Studies.
