Israeli Defence Minister Moshe Yaalon warned Beirut of even tougher reprisals after the army fired shells at Lebanon in response to rockets launched at the Jewish state on Sunday. "We will not tolerate fire from Lebanon on our territory... We consider the Lebanese government and army responsible for this morning's fire," said Yaalon. "The Israeli army responded by firing a large number of shells at the area from where the rockets were fired. If necessary, it will be even tougher. "I would never advise anyone to test our patience and our determination to defend the security of the Israeli people," the minister said in a statement. His remarks came after the army said five rockets were fired at Israel, with at least one of them exploding on its territory without causing any casualties or damage. In retaliation, the Israeli military fired about 20 shells at Lebanon, also without causing any casualties or damage, according to a Lebanese security official. Tension has spiked on the border between the two countries since Lebanese troops shot dead an Israeli soldier driving near the frontier on December 16.