Surat, July 30: Surat Administration has ordered a full day closure of schools, colleges, parks, malls and cinema halls in the city a day after 18 bombs were defused from different places here.

Diamond and textile units are also likely to remain closed.

The administration has tightened the security in the wake of deadly serial blasts in Ahmedabad and Bangalore and the recovery of bombs from residential areas which are usually crowded.

Chief Minister Narendra Modi today visited Surat to take stock of the volatile security situation there.

Yesterday, the bombs were found in and around Varacha area, where most of the diamond polishing units of the South Gujarat city are located.

Surat accounts for 80 percent of the world's diamond polishing business.

Three bombs each were found from Gajera Circle, Mini Diamond Market, Varacha-Kapodra flyover, two each from Heerabaug, Bhavani Circle and one each from Mahidarpura, Sardar Choki, Labheshwar Police Chowki, Santoshinagar and Matavadi.

Forensic experts reportedly said the 18 bombs did not explode because of faulty integrated circuits.

Surat Police Commissioner R M S Brar has asked people to remain on alert.

“I request people to be more alert and immediately inform the police if they find any suspicious material," Brar appealed. He also advised the people to remain indoors.

The bombs recovered yesterday were of low intensity but police have not clarified whether they had timer device or not.

The police yesterday detained four persons from Maharashtra and seized maps of Gujarat, Rajasthan and Punjab and some materials written in Urdu.

Surendranagar District Superintendent of Police Ashok Yadav identified the four as Tariq Ahmed Sheikh, Imrankhan Mohammadkhan, Vazir Khan Pathan and Hakimshah Fakir, police said. (ANI)