The BBC's Alistair Leithead: "The demonstrations ... have taken on much more of a confrontational air to them"
Thai anti-government protesters have built formidable barricades of tyres and sharpened bamboo canes in Bangkok as tensions build in the capital.
But tentative hints of possible new talks between protesters and the government have emerged, as parliament met for the first time in two weeks.
Troops remain behind lines nearby in an increasingly militarised standoff.
The red-shirts are demanding that Prime Minister Abhisit Vejjajiva step down and parliament is dissolved.
But analysts say both sides might feel the need for talks as the prospect of another bloody crackdown looms.
A failed attempt to clear protesters on 10 April left 25 people dead.
Talk of talks
The red-shirts control important intersections of the capital
"We would discuss our standpoint on whether to join another round of truce talks if it is called for by the government," protest leader Nattawut Saikuar was quoted by the Bangkok Post as saying.
The move followed the reported suggestion from another red-shirt leader, Kwanchai Praina, for talks to consider a three-month timeframe for the prime minister to dissolve parliament.
"The government has the upper hand and maybe we should show some flexibility. Maybe parliament can be dissolved in three months," he told Reuters.
"We've heard from insiders in the government that April 26 is their deadline."
The government has previously offered a House dissolution in nine months, while the protesters have said it should be immediate.
"We are open to talks to end the crisis, but not with the government," one of the red-shirt leaders, Jaran Ditthapicha, told Reuters.
The government did not respond to the idea of talks through a third party, but repeated its willingness to talk directly at any time.
"The prime minister is willing to sit down and talk about this, the conditions for holding an election and amending the constitution," said government spokesman Panitan Wattanayagorn.
"Our position is the same. We are open to negotiations and talks providing that they act in a way that does not create tension."
The BBC's Rachel Harvey says the one thing everyone seems to agree on is that the current tense stand-off cannot persist indefinitely.
The "red-shirt" protest camp remains sprawled through Bangkok's shopping district, where several five-star hotels are now refusing guest bookings.
Hundreds of troops are facing tens of thousands of anti-government protesters in clearly defended zones across major junctions in the centre of the city.
"Before we go into the big battle we have to strengthen our own camp because the military will soon attack us," said Mr Nattawut.
He said the protesters expected the army to make its move some time in the next week.
"Red Shirt people will stay here until we win, so if the authorities want to crack down, they don't have to wait for seven days, they can come right now," he added.
Hotels including the Four Seasons, the Intercontinental and the Hyatt Erawan have been surrounded by the red-shirt protest tent city.
Outside the five-star hotels, red-shirted Thais have set up mass food production stations, public bathrooms, massage areas and sleeping zones.
Inside the hotels, no new bookings are being made until at least next Monday.
Most hotel restaurants and major shopping centres have been closed for days.
The Thai army has made explicit its determination to act "decisively" against the protesters, including using live ammunition in certain circumstances.
On Friday, Mr Abhisit put the army commander-in-chief, Anupong Paojinda, in charge of national security
Despite calls from some hard-line parts of the establishment, Gen Anupong has advocated a political solution and said his troops were not planning further crackdowns.