A bomb attack on a bus in Tel Aviv on Wednesday injured more than a dozen people, threatening efforts to secure a ceasefire between Israel and the Palestinian militant group Hamas ruling the Gaza Strip.

The blast in the heart of Israel’s commercial capital occurred on the eighth day of an Israeli military offensive to stop rocket attacks by Palestinian militants in Gaza. It also coincided with a visit to the region by US Secretary of State Hilary Clinton.

The Islamist group Hamas, which controls Gaza, has praised the bomb attack, which Israeli authorities said was carried out by a bomber who placed explosives on the bus and ran away. Police are searching for the suspected bomber and possible accomplices.

Three people were severely wounded in the bomb attack, four suffered moderate wounds and a number of others were treated for minor injures, Israeli medics said.

It was the first bomb attack in Tel Aviv since 2006.

The attack could deal a blow to Egyptian-led efforts to broker a ceasefire between Israel and Hamas, who refuse to hold direct talks.

Ms. Clinton, who is in the region to push for a ceasefire, met with Israeli Prime Minister Benjamin Netanyahu and held talks with Palestinian President Mahmoud Abbas in the West Bank city of Ramallah. She will also hold talks with Egyptian leaders.

Israel has been pounding targets in Gaza since last Wednesday, when it assassinated the head of Hamas’ military wing in an airstrike on his car in the coastal enclave.

It has amassed troops and tanks along the border with Gaza in preparation for a possible land invasion if ceasefire talks fail and rocket attacks continue.

Some 140 Palestinians, including many civilians, have been killed in the violence, the Wafa news agency reported. Four Israeli civilians and one soldier have been killed in the flare-up.

The Israeli military said on Wednesday it had bombed more than 40 tunnels along the Gaza-Egypt border used by militants to smuggle weapons into the territory.

Palestinian militants have fired hundreds of rockets into Israel since Wednesday, many of which were intercepted by Israel’s Iron Dome defence system.

Two rockets hit homes in southern Israel on Wednesday.

More In: International | News