Hamas has called off its six-month ceasefire with Israel and warned it would respond to any attack in Gaza.
Shortly after the shaky six-month truce was formally suspended, the smaller Islamic Jihad group said it had fired three rockets at Israel, which reported no damage or casualties.
This morning, Hamas's Ezzedine al-Qassam Brigades military wing declared its truce was over because 'the Zionist enemy has not respected its conditions'.
Both Hamas and Israel said they would respond if attacked, but neither has indicated any plans go on the offensive at this stage.
Israeli Defence Minister Ehud Barak told the Haaretz newspaper that 'if the quiet continues, there will be quiet. If the lull is shattered, we will act'.
The increased state of alert among security forces and communities around Gaza has been noted in local media, but also uncertainty about the risk of an escalation of violence.
Israel scheduled legislative elections on 10 February 10 after scandal-plagued Prime Minister Ehud Olmert presented his resignation in September.
Defence Minister Ehud Barak has stressed that he sees no urgency in launching a large-scale military intervention in Gaza.
'I do not flinch from an operation and I do not rush into an operation,' he said in an interview with Haaretz.
The truce had been uneasy ever since it went into effect on 19 June, and violence has increased since early November, with 18 Palestinians killed and Israel reporting more than 250 rocket and mortar attacks.
