Students of a fashion institute in Mohali on Thursday alleged that a 55-year-old teacher was sending them vulgar text messages on their cell phones.

They also said he harassed them sexually, promoting authorities to suspend him pending a probe into the matter.

At least 25 students, including 20 girls, of the North Indian Institute of Fashion Technology began an indefinite strike to press for the sacking of assistant professor K Krishnamurthy, who is a head of the department.

The protesting students missed their annual examination, and squatted in front of NIIFT's gate.

Krishnamurthy denied their allegations and said a couple of girls had sent indecent messages to his mobile despite repeated reprimands and him asking them not to do so.

Executive director of the institute, Sanjay Kumar, who is also Punjab's secretary for industries and commerce, ordered Krishnamurthy's immediate suspension in view of prima facie evidence provided by students of his alleged misconduct.

The students said the suspension was not enough and said they wanted nothing short of expulsion.

"We're not going to bargain. It's a matter of our dignity and we'll fight till we get justice," declared Anshu, who was leading the protest.

The students alleged the teacher was sexually harassing girl students for the past couple of months and used to threaten them with dire consequences if they brought it in the open. "He regularly called us and sent SMSs that were far beyond the limits of decency," one of the girls alleged.