More than two million Israeli students returned to schools across the country on Monday as summer vacation came to an end.

As school got underway, a rocket fired from the Gaza Strip exploded in open territory in the Shaar Hanegev Regional Council in southern Israel, causing no damage.

President Shimon Peres visited a fortified high school in Shaar Hanegev on Monday.

"Facing the threat of rockets, you have shown steadfastness in learning, achievements, and creativity," Peres told students. "The state of Israel is proud of you."

Monday's rocket attack came just a day after three Qassam rockets were fired into Israel from Gaza on Sunday. The first rocket exploded on the grounds of a factory in the industrial area of Sha'ar Hanegev, while the second rocket exploded in an agricultural factory. The third rocket was located by a police bomb squad in an open field.

"The school year is opening today," said Shani Cohen, a mother of three from Sha'ar Hanegev. "I have three small children in preschool and elementary school. I can't say I'm calm and relaxed when I know Hamas could, at any moment, remind us of its existence by firing rockets. It's true that the schools themselves are fortified, but having (the children) actually reach the schools is enough to worry me. Yesterday's shooting was only the beginning of 'rocket season,'" she said.

"We will not give them the satisfaction of disrupting the new school year," said Sha'ar Hanegev Regional Council Head Alon Schuster. "Most of the education and public buildings in the council are fortified, including the new high school that will be inaugurated today."

Over summer vacation, workers in the Sha'ar Hanegev and Eshkol regional councils inspected all of the schools under their jurisdiction. "We've left nothing to chance," a security officer said. "We put out a clear order to fix anything in need of repair, in relation to the safety of the students."

The sirens set off by Sunday's rockets caused residents and those working in the factories to seek shelter in designated secure spaces. Despite the direct hit, only one shock victim was reported. According to Roni Elkabetz, all the employees at the factory where he works were present when the rocket hit. "It's been quiet here for several weeks now," he said. "We've already gotten used to a calm life without any rockets, but now the story is repeating itself."

Another employee said that the factories in the area have become accustomed to this situation over the past 12 years. "It's sad that we've come to terms with this, but the fact is we live with it, because this is where our homes and families are."

One of the factories hit on Sunday was also struck a few months ago. One worker was wounded in the June incident, and damage was caused to several structures. All the facilities had since been repaired, but they were damaged again on Sunday.

"It all comes down to luck," said one employee. "There's no way to predict in these cases. It was just unlucky that our factory was hit twice."