Youths pushed and hurled missiles at the former head of the UN nuclear watchdog as he tried to vote in the constitutional referendum which will determine how quickly Egypt can hold elections.

“We don’t want you, we don’t want you,” chanted the crowd of about 60, many of them teenagers.

“I went to vote with my family and I was attacked by organized thugs,” ElBaradei wrote on Twitter. “Top figures of Mubarak’s regime still at large and undermining the revolution,” he said.

Rocks thrown at ElBaradei’s car smashed its rear window as he fled the crowd, a Reuters witness said. He was unable to vote at the Cairo polling station and went elsewhere to cast his ballot.

“They came out of nowhere. They were not in line to vote. They started chanting in unison ‘We don’t want you’ all of a sudden. It looks like it was coordinated,” said Sameh Fathi, 25, who had been waiting in line to vote.