One of the ways Tehran's anti-government "green movement" has been protesting the June election is to spray paint their message in green across the capital. Not impressed, Basij militia members spend their days spray painting over the tags with their own messages, in black.

“The green protestors have to spray in the middle of the night, but the Basij they can do it whenever they like”

Alireza is a journalist and artist from Tehran.

Writing slogans on the walls is a tradition in Iran. When there's a lack of freedom of speech, we express ourselves with spray paint. It's exactly what they did during the 1979 Islamic Revolution. Only then, their message was much more radical. What the green movement is spraying now is very moderate. It's just a way of them saying ‘we're still here'. They've been doing it since the presidential election in June.

The Basij are trying their hardest to remove the messages. They go out every week with black spray paint and scrawl over the messages written in green with pro-government stuff. You see a green message go up on Monday. A week later, it's been scrawled over with a message in black about loving [supreme leader] Khamenei.

The green protestors have to spray in the middle of the night as if they're caught, they'll be arrested. But when the Basij go out with their black paint, they can do it whenever they like. I haven't heard of any protestors being arrested yet as they're very careful and tend to stick to the smaller streets where they can't be seen. They are becoming more adventurous though; recently I've seen green signs appearing in the bigger streets too. Most shop and home owners don't stop them. It's a kind of collaboration.

Alireza sent us these photos, along with descriptions, from Tehran:

"Green = shit". The V symbol, used by the green movement, is transformed into the international symbol for toilets (WC).

"Mousavi." [Opposition leader Mirhossein Mousavi].

"Down with Mousavi."

Whatever was written is now indecipherable.

What was written in green has been written over with "Salout [long live] Khamenei, we adore you".

"I'll die for my leader" (left). On the right, the blacks have turned the V symbol into the Star of David.

Once a V, then a star, then crossed out. The text (crossed out by the greens) reads "When a Basiji dies he takes his dignity with him".

What was "Down with Khamenei" coloured over in black.

"I'd die for my leader, Khamenei", attacked by a ball of green paint.

Toilets again.

The traditional sign for revolution. As long as 30 years ago the hand was used as a symbol of resistance.

The green movement fills plastic bags with green paint and then throws them at the walls, resulting in this effect. 

"Down with Karoubi." [Opposition leader Mehdi Karoubi].

The slightly more sophisticated method of covering messages with white paint.

What did say "Students' day is green" has been crossed out with black.

A green message crossed out at a bus station.

Illegible. Near a secondary school.