I've neglected this blog for a few days, as I've been spending most of my time this weekend trying to keep up with developments in Yemen and responding to these via Twitter and Facebook. But there are a few people who read this blog who don't follow the YPP elsewhere (they really should, though), so I thought it would be useful, while I work on my next piece of forward-looking analysis, to post some of my recent updates here. Things are going to change a great deal in the next few days, so this post will help us remember what came before. The excerpts below are in reverse chronological order. All times are Yemen time (GMT +3).

2/20 10:30pm: Protests in San'a are very organized, and have persisted throughout the day. This looks like a turning point, the first day of sustained, peaceful occupation of public space in San'a. If San'a and Ta'iz can both sustain such protests, a significant shift will have occurred. Large demos are also reported in Ibb today.

The military seems to be in control of Aden, though large protests continue in every district of the city. One protester was reported killed by gunfire in the Shaykh Othman district, north of the city.

2/20  8:00pm: San'a demonstrations are more peaceful today. Protesters at the university massively outnumber thugs, who have seemingly given up for the day. President Saleh addressed tribal leaders this morning; foreign journalists were invited to attend as Saleh tries to undo the damage to his image after journos were attacked and intimidated earlier this week. No concrete news from Aden, but last night the city was surrounded by military forces and phone service was cut. A major leader of the Southern Movement, Hasan Baumi, has been kidnapped by security forces for the second time this year, if I'm not mistaken.

2/19 12:00pm: Tweeters from Aden report two children are among the latest casualties, shot by security forces.

2/19 10:39pm: Security forces in San'a have just now started shooting at protesters near al-Zubayri bridge. Students and others were marching away from the University. Police told them to disperse, which they did. Then police began shooting.

Yemen's main opposition bloc, the Joint Meeting Parties, has announced that it stands with protesters in advocating an end to the Saleh regime. It will not engage in dialogue until the protesters' demands are met.

2/19 9:20pm: Yemen gov. says that if the regime falls, anarchy will prevail and "tribes may raid the capital." Translation: "if you keep protesting, we will pay loyal tribes to raid the capital." It's happened before. The struggle between the president and other leaders for the loyalty of northern tribes may determine the success or failure of this movement, especially in San'a. For related analysis see: http://bit.ly/eL6oWy

2/19 7:30pm: One protester has been killed and at least ten injured after security forces opened fire on protesters at San'a University [it was later reported that all of those injured had in fact survived]. According to Al Jazeera, guns have been used today by both sides. It's unclear to me whether clashes are still going on.

The military has cut off the city of Aden and imposed a curfew there. Protesters have burned government buildings and continue to gather.

2/18 2:15am: As of now it seems that protests/clashes might still be going on in some neighborhoods of Aden. Sources indicate that at least 2 have been killed there today. Either one or no deaths from the grenade in Ta'iz, and around 80 injuries. Protesters there are maintaining a round-the-clock occupation of the public square there. In San'a it seems that there were no night-time clashes. Protesters were attacked and beaten this afternoon.

2/18 10:00pm: Witnesses say army and special forces have emerged on the streets of Aden. We may see a much more intense crackdown tonight.

2/18 8:36pm: Today's protests in San'a: protesters stopped, attacked, turned back by police. Other sources claim greater violence against protesters than this report indicates.

2/18 6:18pm: At least one killed in Aden today. That's three days in a row with protesters killed there. Government has appointed a new head of security for Aden, a man who yesterday blamed Southern Movement activists for deaths.

2/18 5:52pm: A man said to be an employee of the mayor of Ta'iz threw a grenade into a group of peaceful demonstrators there earlier today, killing one and injuring at least thirty. Marib Press also reports that the entire army garrison near Ta'iz was emptied as ruling party officials paid soldiers to participate in mandatory pro-regime rallies.

2/18 5:42am: Protest organizers in all of Yemen's major cities have called for massive protests today. Most groups had planned events for the 24th or 25th, but events seem to have pushed the timetable ahead. This could mean that organizers have less control over the protests (that was certainly true in San'a yesterday).

2/18 12:04am: "Tens of thousands" of demonstrators have gathered in Ta'iz's Tahrir Square, and plan to remain there as long as possible. The locals have been joined by crowds from all over the province, and demonstrators have begun to form committees to protect the crowd from security forces.

2/17 10:21pm: A shaykh of the northern Hashid tribal confederation and member of the al-Ahmar family has said that his group is ready to intervene to protect demonstrators if the government continues its crackdown. This is likely more a bargaining maneuver than a viable threat, but we'll see.

2/17 6:30pm: Today seems to have been a very bad day in San'a. Lots of violence between pro- and anti- government demonstrators on the streets, but it seems to have ended peacefully. It's not clear to me whether Aden was calmer today [it wasn't].