Chennai, April 29 : Tamil Nadu's semi-urban towns -- Tirunelveli, Tuticorin, Dharmapuri, Krishnagiri, Tenkasi and Nagapattinam -- continued to witness surge in Covid-19 cases. While in the past 15 days, urban districts including Chennai and Coimbatore reported an 18 per cent increase in Covid cases, semi-urban districts including Tirunelveli and Tuticorin logged 22 per cent rise in the infections. Tuticorin reported 5,657 fresh Covid cases by April 28, whereas it had only 193 cases in March. Health officials said that the Covid spike in the semi-urban districts can be attributed to the huge public gathering during the election rallies held across these districts as compared to the people's participation in urban districts. Mukundarajan, a doctor in a private hospital in Tuticorin, while speaking to IANS said: "During election rallies people were not wearing masks or maintaining social distancing and no sanitisers were used. Public were on the roads most of the time and there were no restrictions on people freely interacting with others. These have jointly led to a higher increase in the surge of Covid cases." Beisdes, weddings and religious functions flouted Covid norms in areas including Dharmapuri, Tenkasi and Tuticorin. Rajeswaran PK, who runs a shop near a Temple at Tenkasi, said, "We did brisk business during the Mariamman koil festival here which was held last month. People thronged in large numbers violating Covid protocols." However health officials are of the opinion that higher numbers being detected even in small towns is an indication that the testing are done properly and this has led to more positive cases. A senior health officer with the Tamil Nadu governemtn working at Tuticorin district, told IANS on condition of anonymity: "The testing has increased many fold even in rural and semi-urban towns and this is the reason for a surge in Covid cases. However these positive cases have to be immediately isolated and quarantined. This will help the reduction in the pandemic and we can bring it down within a few weeks time." The health officials in all the semi-urban towns are on a high alert following the detection of large numbers of Covid positive cases and are creating awareness across the towns on social distancing, wearing masks and use of sanitisers along with vaccination as the only means to prevent the disease from spreading. /IANS