At least four people died and seven others were injured in three explosions in the Nepali capital, Kathmandu, officials say.
The three blasts – one in the centre and two on the outskirts – took place on Sunday afternoon local time.
Improvised or crude explosive devices are believed to have been used to set off the blasts, police said.
One official told reporters a Maoist splinter group was under suspicion after pamphlets were found nearby.
The same group is alleged to have carried out an explosion in February which killed one person in Kathmandu.
However, no one has claimed responsibilities for the attacks.
Police official Shyam Lal Gyawali said three of those killed died “on the spot”, while the fourth died in hospital.
The pamphlets were found at a home on the outskirts of the city, where the first blast took place, he added.
Student Govinda Bhandari, 17, told Reuters news agency: “I heard a big noise and rushed to the spot to find the walls of a house had developed cracks due to the impact of the blast.”
Just one person died in the initial explosion, while three died in a second incident near a hairdressers in the city centre.
The third blast happened several hours later and is reported to have injured two members of the group transporting an explosive device.
Security forces have sealed off the locations of the blasts and say investigations are under way.
Since a decade-long civil war ended in 2006, Nepal has been relatively peaceful, with the main group of the former rebels joining the ruling government party the next year.
However, some have now broken away, saying their leaders are betraying their original revolutionary ideals.