JERUSALEM (AP) — Israel says Palestinian militants in the Gaza Strip have fired a rocket into the country's south. There were no reports of casualties or damage.

The military says the rocket fell in the southern Israeli town of Sderot on Friday evening.

In response, Israeli tanks and aircraft attacked three sites belonging to the Hamas militant group. The Israeli military said the targets were “infrastructure used for underground activity," without elaborating.

The fire shattered weeks of a rare total calm along the often-volatile frontier between Israel and Gaza, a coastal territory ruled by Hamas.

No Palestinian group has claimed responsibility for the launching but Israel usually blames Hamas for any attack originating from the enclave it controls.

The calm had prevailed as Gaza and Israel struggle to contain the spread of the coronavirus. Nine cases of the virus have been confirmed in the overcrowded, blockaded Gaza Strip amid fears that its under-resourced health system will not be able to handle an outbreak. Israel has recorded 12 deaths from COVID-19, the illness caused by the virus, and over 3,000 infections.