Israeli Health Ministry confirmed on Tuesday the first case of swine flu and raised the preparedness level to 4 out of 6.

A 26-year-old man who had returned from Mexico with flu-like symptoms was diagnosed with the virus, Israel Radio reported.

The man was in stable condition after two days of quarantine in a Netanya hospital, but not isolated from other patients, said the report.

Another Israeli man has also been quarantined until further notice in a hospital in Kfar Sava, after his travel from Mexico with flu-like symptoms.

Meanwhile, Israel Health Ministry decided to raise the preparedness level for swine flu from Phase 3 to Phase 4. The change in preparedness levels did not involve any serious operative changes, since the ministry had contingencies for such a situation, according to a statement released from the ministry on Tuesday.

On Monday, the World Health Organization raised its global alert level from Phase 3 to Phase 4, signaling the swine flu virus was spreading from human to human in community outbreaks, but it stopped short of declaring a full-blown pandemic.

According to the World Health Organization's program for dealing with possible influenza pandemics in such cases, Phase 3 deals with preparedness for only sporadic infection of humans by animals, whereas Phase 4 deals with readiness for virus spread caused by sustained human to human transmission.