Rand Paul vows to block spy laws in US Senate debate

The US Senate is meeting in a rare weekend sitting to try to avert the expiry of anti-terrorist laws that let security services collect phone data.

Senators have failed to extend key provisions of the law, known as the Patriot Act, which are set to expire at midnight local time (04:00 GMT).

Senators are still debating the USA Freedom Act, a replacement bill that would water down bulk data collection.

However, Republican US presidential hopeful, Rand Paul, has vowed to delay a vote on the act.