Thick plumes of black smoke billowed into the sky after the blaze broke out at the ceramic tile manufacturing unit. Over 130 people were injured in the blast.
External Affairs Minister S Jaishankar tweeted: "Have just received the tragic news of a major blast in a ceramic factory "Saloomi" in the Bahri area of the capital Khartoum in Sudan. Deeply grieved to learn that some Indian workers have lost their lives while some others have been seriously injured.
"The Embassy representative has rushed to the site. A 24-hour emergency hotline +249-921917471 has been set up by @EoI_Khartoum. Embassy is also putting out updates on social media. Our prayers are with the workers and their families."
At least 68 Ind were working at the ceramic factory 'Seela' in Bahri area of Khartoum at the time of the LPG tanker blast on Tuesday evening.
The Indian embassy in Khartoum said: "As per latest reports, but so far not confirmed officially, 18 are dead."
It added that "some of the missing may be in the list of dead which we are still to receive as identification is not possible because of the bodies being burnt".
The embassy listed seven Ind as admitted to the Al Amal hospital in Bahri, Khartoum, including three in the ICU.
It listed 16 Ind as missing, and gave a list of 34 Ind as having survived the accident.
Most of the Ind are from Bihar, UP, Rajasthan, Gujarat and Tamil Nadu.
Prime Minister Narendra Modi expressed his anguish at the deaths. "Anguished by the blast in a ceramic factory in Sudan, where some Indian workers have lost their lives and some are injured. My thoughts are with the bereaved families and prayers with the injured. Our Embassy is providing all possible assistance to those affected," he tweeted.
West Bengal CM Mamata Banerjee tweeted: "Saddened at the demise of 18 Ind in LPG tanker blast in Sudan. My condolences to the bereaved families. Our country's workers are placed in different parts of the world and face various risks. May all stay safe."
Rajasthan CM Ashok Gehlot also tweeted his anguish over the accident.
( With inputs from IANS )