Israel has vowed to hit Hamas leaders "wherever they are" and accelerate work on its West Bank barrier after the deadliest suicide bombings for months.
Both bombers are said to have come from Hebron in the West Bank
Near-simultaneous explosions on two buses in Beersheba, southern Israel, killed 16 in attacks claimed by Hamas.
The militants said they were avenging the deaths of two of their leaders.
An Israeli helicopter fired a missile in the Gaza Strip after soldiers demolished housing connected to the two Palestinians named as the bombers.
The helicopter fired at least one missile in the direction of the Khan Yunis refugee camp in the south of the Gaza Strip on Wednesday evening as Israeli ground troops manoeuvred nearby, Palestinian witnesses said.
There were no confirmed reports of casualties.
Correspondents say that, since the deaths of Ahmed Yassin and Abdel Aziz al-Rantissi in March and April, Israel had put on hold further killings of high-echelon Hamas figures.
"The policy now is to hit Hamas leaders wherever they are," a senior security source is quoted as saying on Wednesday.
Israeli officials are pointing the finger of blame at Syria, where Hamas political chief Khaled Meshaal has since emerged as the movement's undisputed leader.
The local leaders in Gaza, Mahmoud al-Zahhar and Ismail Haniyeh, have gone underground since the Yassin and Rantissi assassinations.
Israeli forces closed off Hebron overnight and blew up the home of Ahmed Qawasmeh, one of the bombers who struck in Beersheba.
Troops also partially demolished the house of the second suicide bomber, Nassem Jabari. However, they did not dynamite the building for fear that it could wreck other families' homes as well, reports said.
It was the first time Beersheba has been hit by bombers
The Palestinian Authority has condemned the attacks - the first suicide bombings in Israel since March.
But in Gaza, thousands of Hamas supporters celebrated, saying their slain leaders could "now rest in peace".
Suicide bombers have killed hundreds of people in Israel since the start of the of the Palestinian uprising nearly four years ago.
It has become a standard Israeli tactic in the wake of a suicide bombing to destroy the bombers' homes.
Tuesday's attacks shattered a period of relative calm inside Israel, which officials put down to the construction of the West Bank barrier and repeated attacks against militant groups.
Prime Minister Ariel Sharon called a late-night security meeting after the bombings.
His chief spokesman, Ranaan Gissin, is quoted as saying that work on the southern part of the West Bank barrier will now be speeded up.
"If there was a fence in that area, it would have been much harder to get into Beersheba from Hebron," Mr Gissin is quoted as saying to the AFP news agency.
The Israeli government has come in for heavy criticism over the barrier's route, with the International Court of Justice ruling that parts built on occupied land are illegal and should be torn down.
Sources close to Palestinian leader Yasser Arafat said the Israelis had been looking for excuse to continue with the construction.
Mr Arafat condemned the attack, saying operations that targeted Israeli civilians were against "the Palestinian national interest".