TRINCOMALEE (AFP) - Suspected Tamil Tiger rebels set off a powerful bomb killing 11 people and wounding 29 in Sri Lanka's east late Friday, a day ahead of a crucial local poll in the area, the military said. The blast took place inside the crowded "New City CafT" in Ampara town, 350km from Colombo, the Defence Ministry said, blaming the attack on separatist rebels. Minutes before the blast, a convoy carrying a key government minister had passed the area, eyewitnesses said but police said the target of the attack was unclear. The injured were rushed to the nearby Ampara hospital, police at the scene said, adding the nine men and two women were among the dead. The attack came despite heavy security on Sri Lanka's east coast as residents of Batticaloa, Trincomalee and Ampara prepared to cast their ballots on Saturday (today) to elect officials to run the eastern provincial council. The local polls, the first in the region for 20 years, come after government troops wrestled the island's east from the Liberation Tigers of Tamil Eelam (LTTE) last July. The election is seen as a litmus test for President Mahinda Rajapakse's hawkish government as it escalates the war against the rebels to regain vast swathes of land under guerilla control in the north. "This is another cowardly attempt of the LTTE to disrupt normalcy in the area as the government (is) scheduled... to establish democracy in the eastern province," the Ministry said after the bombing. Meanwhile, helicopter gunships provided air cover Friday for ground troops advancing into rebel areas of northern Sri Lanka where at least 48 rebel guerillas were killed, the Defence Ministry said. Air force Mi-24 helicopters flew support as soldiers moved on Alankulam, in Mannar district, killing 33 rebels and injuring 40, a Ministry statement said. The military said three soldiers died, five were wounded and another five reported missing in the pre-dawn attack. However, the LTTE said two of their cadres were wounded when guerillas repelled the attack killing 30 government soldiers and injuring five. Elsewhere, two soldiers died as government troops on Friday took control of Adampan town, also in Mannar, killing 15 more Tamil rebels, the Ministry said. Friday's fighting raised the number of rebels killed by government troops since January to 3,521, according to the ministry, which lists 266 soldiers as dead over the same period. The Ministry casualty tolls cannot be independently verified since Colombo prevents media and rights groups from visiting the embattled areas. Fighting has worsened since January, when Colombo pulled out of a six-year truce. The LTTE have been fighting for a Tamil homeland since 1972 in a brutal campaign that has left tens of thousands dead.