At least eight people have been killed in new attacks in Sri Lanka since Sunday, officials say.
Tensions have risen sharply in recent weeks
Two suspected Tamil rebels were shot dead in Batticaloa in the east, while two Sinhalese guards were killed near Vavuniya in the north, police say.
In the worst of Monday's other attacks, a young mother was hacked to death near
Batticaloa, police said.
The Tamil Tigers last week called off the latest round of peace talks that had been due to start Monday in Geneva.
More than 100 people have been killed this month in escalating violence in the north and east of the country, about 70 of them members of the security forces.
The latest violence follows the killing of six farmers on Sunday near Vavuniya, for which rebels were blamed.
Police said two guards, who worked in a Sinhala-majority village, were attacked on Monday as they were returning home after attending the funeral of relatives who were hacked to death by unknown people on Sunday.
Unidentified gunmen are also reported to have killed a Tamil 15km (nine miles) north west of Vavuniya on Sunday night.
In the eastern town of Batticaloa, Sri Lankan troops shot and killed two suspected rebels as they were laying mines, the government said.
Police have accused rebels of killing the woman, who had been nursing her baby, in Seruwila near Batticaloa.
An office clerk was killed by unidentified gunmen in another attack in the area, police said.
In the north near Jaffna, a soldier hurt in an attack on Sunday also succumbed to injuries, the military said.
The government blamed the Tigers for killing the six male civilians on Sunday, saying the "senseless killings" were aimed at inflaming ethnic tensions.
Correspondents described the attack as the worst since Tamil Tiger rebels and the government began a ceasefire in 2002.
However, the Tigers told the BBC they were not involved in the deaths of the six villagers.
Increasing attacks on civilians have sparked inter-communal violence in the east, with Sinhala mobs burning and looting Tamil homes and shops, reports the BBC's Dumeetha Luthra from the Sri Lankan capital, Colombo.
Thousands of Tamils in the east of Sri Lanka are reported to have fled their homes in fear of reprisal attacks.
Tension in the Trincomalee district has been high since 16 people died in bombings and rioting in Trincomalee town in the middle of April.
Police say Sinhala villagers in the area have fled, fearing further attacks.
The east of Sri Lanka is falling apart, with daily attacks against the military blamed on Tamil Tiger rebels, our correspondent says.
The Tigers have been fighting for an independent homeland for over two decades. The government has made it clear that the island must remain unified.
More than 64,000 people have died in the conflict.