Several beaches in north suburban Evanston were closed Friday due to bacteria in the water.

Water at four of the city’s six beaches were closed for elevated levels of E. coli, although their sandy parts remained open, a spokesperson for Evanston said.

The closed beaches include Lee Street Beach, Greenwood Street Beach, Clark Street Beach and Lincoln Street Beach.

Water at the Lighthouse and South Boulevard beaches tested safe and remained open for swimming, the spokesperson said.

The city will continue to test bacteria levels at the beaches, and will announce when the water is safe again for swimming.

Many types of E. coli are harmless to humans, although some can cause diarrhea and other illnesses, according to the Centers for Disease Control and Prevention.