Two Sydney high schools in lockdown

Students will return to two high schools in southwest Sydney a day after they went into lockdown over social media threats.

Police attended East Hills Boys High School in Panania and Sir Joseph Banks High School in Revesby on Tuesday but refused to detail the timing and content of the threats.

Parents were advised their children were safe but had the option of picking them up from the neighbouring schools, a NSW Department of Education spokesman said in a statement.

Since the terror-related murder of police accountant Curtis Cheng on October 2, there have been countless threats made against major Sydney sites.