BALTIMORE (WJZ) — Baltimore City Schools is working to keep their network secure after a ransomware cyber attack forced Baltimore County Schools to close on Wednesday.

The school district said they have blocked all emails coming in from Baltimore County Schools, and their IT department is monitoring for other suspicious emails.

READ MORE: Former Harford County Councilman, Town Commissioner 'Capt'n Jim' Dies At 42, Visitation April 30

Baltimore City Schools is asking anyone who believes they received a suspicious email to contact them immediately.

The school district also announced students and staff can use programs like iReady, Imagine Math and Amplify online.

MORE NEWS: Nick Mosby Introduces Bill To Increase Work Opportunities For Baltimore City Residents

There is still no word on who is behind the ransomware cyber attack at Baltimore County Schools, or how much money they want.

CBS Baltimore Staff