Sri Lanka's military has said crossing points to Tamil Tiger territory have reopened and that it had ceased bombing rebel targets.
However, it did not rule out more attacks as the island teeters on the brink of war.
The border crossings were closed by the army in the aftermath of the suicide attack in Colombo, effectively cutting off the northern government held enclave of Jaffna.
Yesterday, thousands of people were stranded and the normally busy crossing point was deserted.
The closing of the road stopped food and fuel deliveries to northern Jaffna peninsula forcing power cuts.
While the heavy firing in eastern Sri Lanka seen on Tuesday and Wednesday has ceased, both sides have vowed to retaliate if attacked again.
A suicide bomb attack that killed 10 and wounded the army commander on Tuesday was followed by air strikes on Liberation Tigers of Tamil Eelam (LTTE) territory in the east.
The United Nations says thousands have fled their homes.
International truce monitors say both sides need to act urgently to save a four-year-old ceasefire.
