Hundreds of ultra-Orthodox Israelis demonstrated in Jerusalem, burning garbage containers and throwing stones at police to protest the annual gay parade planned in the city on Thursday, Israel Radio reported.
Hundreds more held similar protests in the ultra-Orthodox Tel Aviv suburb of Bnei Brak.
Police arrested at least two of the protesters in Jerusalem and another two in Bnei Barak, the radio said.
The protests escalated Wednesday after Israel's supreme court rejected a petition seeking to stop the march, due to be held on Thursday in Jerusalem.
Some 5,000 members of Israel's gay community are expected to attend, protected by as many as 7,000 police officers.
The precaution comes after protests leading up to the parade last year turned violent for days in advance, and leaders of the Jerusalem Open House, which organises the event, were forced to hold it in a closed stadium far removed from the city centre to ease the tensions.