Google Inc on Tuesday began a public search for an executive missing in Cairo, where the Internet company has offered tools to help Egyptians communicate amid chaotic protests.

Google, which launched a way for Twitter users to communicate without Internet access, said on Tuesday that Wael Ghonim, head of marketing for the Middle East and North Africa, has not been seen since late Thursday in central Cairo.

The safety of our employees is very important to Google, so if anyone has any information please call the following UK number: +44 20 7031 3008, Google said in a statement.

At least 140 people have died since demonstrations against the 30-year rule of Egyptian President Hosni Mubarak began last Tuesday, most in clashes between protesters and police.

A person familiar with the matter told Reuters Ghonim is based in Dubai and was in Cairo for personal reasons.

Twitter messages last week from an account with the user name Wael Ghonim criticized the Egyptian government and showed solidarity with protesters rallying against Mubarak.

Sleeping on the streets of Cairo, trying to feel the pain of millions of my fellow Egyptians, read a January 25 tweet.

The Egyptian government started to take really stupid actions that will result in nothing but encouraging more people to protest, read another on January 26.

Google said it could not confirm the Twitter account belonged to Ghonim. The last tweet from the account was on January 27.

The Egyptian government has cut off Internet access in an attempt to restrict communications among protesters.

To work around the Internet communications restrictions, Google launched a special service for Egypt to allow people to dial a telephone number and leave a voice mail which would then be sent on Twitter and could be heard on telephones.

Like many people we've been glued to the news unfolding in Egypt and thinking of what we could do to help people on the ground, read a post on Google's official corporate blog on Monday announcing the so-called speak-to-tweet service.

Google has temporarily closed its office in Cairo to ensure the general safety of its employees, the person familiar with the matter told Reuters.

President Hosni Mubarak said in a speech on Tuesday he will not seek reelection in September, but it was far from clear that would satisfy the hundreds of thousands of protesters who had gathered across Egypt to call on him step down now.

On Monday, the Egyptian army said it would not take action against demonstrators.

(Reporting by Alexei Oreskovic; Editing by Jackie Frank and Todd Eastham)

Artificial intelligence Google Egypt