The lockdown, announced by Chief Minister K Palaniswami on Monday as part of the government's measures to tackle COVID-19, was originally scheduled to be in force till March 31, 2020.
"The lockdown and related orders announced till March 31 are being extended till April 14," an official release here said.
The government warned of stringent action against those violating home quarantine protocols, even as it assured them that their essential needs will be met.
The decisions were taken at a review meeting chaired by the Chief Minister with various department heads and district collectors to discuss the steps taken to tackle the spread of the virus, the release said.
To implement the lockdown, the section 144 of Cr.Pc. was issued. It prohibits assembly of more than five persons.
On Tuesday, Modi had announced the 21-day lockdown to halt the spread of the virus, which has so far affected over 600 people and killed 13 in the country.
Besides the extension of the lockdown, a number of other directives were also issued to the officials by the chief minister at the review meeting.
These included the constitution of nine teams headed by senior Indian Administrative Services (IAS) officers to ensure delivery of essential services to the public during the lockdown.
Further, the "list of 54,000 persons who had come from abroad (apparently Indians) has been provided to the (respective) district collectors. They (such persons) should be isolated at their homes," it said.
These persons will be monitored to ensure they don't step out of their homes, the release added.
Those who had come in contact with COVID19 positive cases have been quarantined at their homes and the district collectors should take steps to provide them with required essential items, and with due protection, it said.
Anyone violating home quarantine will be levied with fine, and will also have to face penal action, the government warned.
It reiterated that app-based food delivery firms like Zomato, Swiggy and Uber Eats cannot deliver food at homes.
But there was no bar on delivery of dry ration and medicines and other essential items by e-commerce firms like Grofers, Big Basket and Amazon, besides by local groceries and cooperative outlets. Also, supply of food from small outlets to the elderly and sick will be allowed.
Provision of two months stock of medicines to pregnant women and others dependent on government hospitals was among the various other decisions taken at the meeting.
Laying stress on social distancing, the government said it should be strictly followed in grocery and vegetable shops.
The farm sector has been declared 'Exempted' from the lockdown and therefore there was no ban on related activities.
"All these decisions have been taken with the noble intention that people are not affected anyway (by the virus spread). Realising this, they should strictly follow the orders," it added.
The concept of isolation, awareness and stay at home should be sincerely followed, the release quoted Palaniswami as appealing to the people.
Meanwhile, the government announced there was no restriction on the duration that eateries and department stores stayed open in the day.
"They have been allowed to function all through the day. The timings have not been cut short," it said.