Israel says it conducted roughly a hundred airstrikes on Hamas targets in Gaza overnight Thursday into Friday, after militants attempted rocket attacks on the city of Tel Aviv.
The rocket attacks caused no damage though and what sparked the incident is unclear.
Hamas denies responsibility and a security official, speaking to Reuters anonymously, says the first rocket fired from the Palestinian side appears to be an accident.
There was no intent to attack Israel, according to the source.
Israeli media are carrying similar reports.
It's also not clear what the damage to Hamas was.
Israel said it hit a regional headquarters and weapons depot among other targets but some had already been evacuated.
Gaza health officials say four people were wounded.
If it was an intentional attack, some Israeli analysts speculated that Palestinian militants opposed to any peace between Hamas and Israel may have done it.
And Prime Minister Benjamin Netanyahu's right wing political rivals seized on the incident to call for the assassination of Hamas leaders.
The last time Hamas rockets were directed against Tel Aviv was during the war five years ago.
The exchange of fire prompted bomb shelters to open in Tel Aviv as a precaution.